YES!

DirectPlay did the trick.

For reference:

On windows 10 64b, install freelancer, then apply the No-CD patch.
Try to launch freelancer. If it exits without showing any display (an error code c0000005 can be found in the event observer), then install manually DirectPlay:
Open C:\Windows\System32\OptionalFeatures.exe, and under “Inherited Components” (or legacy ?), check DirectPlay.

Launch Freelancer to check that it works.
I applied then the JFLP patch…. its soooo beautiful now, I can’t wait to relive this adventure !

Many thanks for your support.

Thanks @Bolte and @Adoxa for the support.

In short:

1. I tried a complete reinstall on my machine, following Bolte recos, without success (details below)
2. I tried to install it on a VirtualBox VM with Win10 (running on my machine) - it works (after promting for Direct Play install)
3. Next step: I will search whether DirectPlay is installed on my system, and try to reinstall it. I will post the result here.

===== Details (this failed):
a) Completely Uninstalled Freelancer, Cleanup registry to remove all FL data (compat info…), Cleanup of freelancer data in C:\ProgramData, C:\Users\Philippe\AppData,
delete C:\Users\Philippe\AppData\Local\VirtualStore\Program Files (x86)\Microsoft Games\Freelancer\EXE
C:\Users\Philippe\AppData\Local\CrashDumps\freelancer

b) Updated Nvidia GeForce Drivers to latest
c) Stopped Windows Defender, Rebooted in Safe Mode, Installed FL As Admin.

d) Start FL (normal, or AsAdmin): Idem, nothing displays, the mouse pointer returns to inactive after a few seconds. No DirectPlay prompt, just a record in Windows Event Observer.
Same result if I comment the ‘movies’ lines in freelancer.ini

From the Event Observer:
Event Type: BEX, ID of CAB: 0, PCH_69_FROM_ntdll+0x000722CC, same code c0000005, ExceptionData: 00000008

This code c0000005 seems to be DEP (Data Execution Prevention)
=> System info > Advanced > Performances > DEP : Added Freelancer.exe to the Exclusion List.
Idem, fails to start but now with an EventType=APPCRASH in the Event Observer record.

Thanks for the idea, would have been a good explanation. Unfortunately, it still fails. The only difference in the error reports is the exception offset, but I have absolutely no idea on how to use this information, and whether it is significant at all

Sig[7].Name=Exception Offset
Sig[7].Value=PCH_1F_FROM_ntdll+0x000722CC
DynamicSig[2].Name=Locale ID
DynamicSig[2].Value=1033

Even with the No-CD patch, I couldn’t run it on my system, it crashed without even opening a window. This was not the Secdrv issue (as seen in the Windows error logs), but a generic APPCRASH error whose cause I could not determine (see below if interested – don’t lose time on this, though, especially if I am the only one with this kind of issue).
I tried many of the suggestions I could find here on starport and elsewhere, to no avail. So, I resolved to try the VM path, and published the result, for others who might run into the same difficulties.

---------- (windows error report - WER file)
Version=1
EventType=APPCRASH
EventTime=131486496671359365
ReportType=2
Consent=1
UploadTime=131486496679393138
ReportStatus=268435456
ReportIdentifier=0cd3031a-60fb-46f3-baa6-7db485371c79
IntegratorReportIdentifier=b428de40-894f-49c8-9b54-23e9129ae52a
Wow64Host=34404
Wow64Guest=332
NsAppName=Freelancer.exe
AppSessionGuid=000032a8-0001-0017-8589-58a54522d301
TargetAppId=W:00063d0579e0158d622547d79e2e2f8ebc9400000904!0000eab2f12172058795f6cd6a8e175e0266824bde50!Freelancer.exe
TargetAppVer=2003//02//04:19:58:49!21e253!Freelancer.exe
BootId=4294967295
ServiceSplit=3539031
TargetAsId=19774
Response.BucketId=785401b2ce89dfaaa636a7a42a74c790
Response.BucketTable=1
Response.LegacyBucketId=107773220228
Response.type=4
Sig[0].Name=Nom de l’application
Sig[0].Value=Freelancer.exe
Sig[1].Name=Version de l’application
Sig[1].Value=1.0.1223.11
Sig[2].Name=Horodatage de l’application
Sig[2].Value=3e401b79
Sig[3].Name=Nom du module par défaut
Sig[3].Value=StackHash_2beb
Sig[4].Name=Version du module par défaut
Sig[4].Value=0.0.0.0
Sig[5].Name=Horodateur du module par défaut
Sig[5].Value=00000000
Sig[6].Name=Code de l’exception
Sig[6].Value=c0000005
Sig[7].Name=Décalage de l’exception
Sig[7].Value=PCH_65_FROM_ntdll+0x000722CC
DynamicSig[1].Name=Version du système
DynamicSig[1].Value=10.0.15063.2.0.0.768.101
DynamicSig[2].Name=Identificateur de paramètres régionaux
DynamicSig[2].Value=1036
DynamicSig[22].Name=Information supplémentaire n° 1
DynamicSig[22].Value=2beb
DynamicSig[23].Name=Information supplémentaire n° 2
DynamicSig[23].Value=2beba6fb4680d73a8c78ca7c24ccdb46
DynamicSig[24].Name=Information supplémentaire n° 3
DynamicSig[24].Value=cfd7
DynamicSig[25].Name=Information supplémentaire n° 4
DynamicSig[25].Value=cfd7ad72b02c318914bfc4ba719d4940
UI[2]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\Freelancer.exe
UI[3]=Freelancer a cessé de fonctionner
UI[4]=Windows peut rechercher une solution au problème en ligne.
UI[5]=Rechercher une solution en ligne et fermer le programme
UI[6]=Rechercher ultérieurement une solution en ligne et fermer le programme
UI[7]=Fermer le programme
LoadedModule[0]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\Freelancer.exe
LoadedModule[1]=C:\WINDOWS\SYSTEM32\ntdll.dll
LoadedModule[2]=C:\WINDOWS\System32\KERNEL32.DLL
LoadedModule[3]=C:\WINDOWS\System32\KERNELBASE.dll
LoadedModule[4]=C:\WINDOWS\SYSTEM32\apphelp.dll
LoadedModule[5]=C:\WINDOWS\AppPatch\AcLayers.DLL
LoadedModule[6]=C:\WINDOWS\System32\msvcrt.dll
LoadedModule[7]=C:\WINDOWS\System32\USER32.dll
LoadedModule[8]=C:\WINDOWS\System32\win32u.dll
LoadedModule[9]=C:\WINDOWS\System32\GDI32.dll
LoadedModule[10]=C:\WINDOWS\System32\gdi32full.dll
LoadedModule[11]=C:\WINDOWS\System32\msvcp_win.dll
LoadedModule[12]=C:\WINDOWS\System32\ucrtbase.dll
LoadedModule[13]=C:\WINDOWS\System32\SHELL32.dll
LoadedModule[14]=C:\WINDOWS\System32\cfgmgr32.dll
LoadedModule[15]=C:\WINDOWS\System32\shcore.dll
LoadedModule[16]=C:\WINDOWS\System32\RPCRT4.dll
LoadedModule[17]=C:\WINDOWS\System32\SspiCli.dll
LoadedModule[18]=C:\WINDOWS\System32\CRYPTBASE.dll
LoadedModule[19]=C:\WINDOWS\System32\bcryptPrimitives.dll
LoadedModule[20]=C:\WINDOWS\System32\sechost.dll
LoadedModule[21]=C:\WINDOWS\System32\combase.dll
LoadedModule[22]=C:\WINDOWS\System32\windows.storage.dll
LoadedModule[23]=C:\WINDOWS\System32\advapi32.dll
LoadedModule[24]=C:\WINDOWS\System32\shlwapi.dll
LoadedModule[25]=C:\WINDOWS\System32\kernel.appcore.dll
LoadedModule[26]=C:\WINDOWS\System32\powrprof.dll
LoadedModule[27]=C:\WINDOWS\System32\profapi.dll
LoadedModule[28]=C:\WINDOWS\System32\OLEAUT32.dll
LoadedModule[29]=C:\WINDOWS\System32\SETUPAPI.dll
LoadedModule[30]=C:\WINDOWS\SYSTEM32\MPR.dll
LoadedModule[31]=C:\WINDOWS\SYSTEM32\sfc.dll
LoadedModule[32]=C:\WINDOWS\SYSTEM32\WINSPOOL.DRV
LoadedModule[33]=C:\WINDOWS\SYSTEM32\bcrypt.dll
LoadedModule[34]=C:\WINDOWS\SYSTEM32\sfc_os.DLL
LoadedModule[35]=C:\WINDOWS\AppPatch\AcGenral.DLL
LoadedModule[36]=C:\WINDOWS\System32\ole32.dll
LoadedModule[37]=C:\WINDOWS\SYSTEM32\UxTheme.dll
LoadedModule[38]=C:\WINDOWS\SYSTEM32\WINMM.dll
LoadedModule[39]=C:\WINDOWS\SYSTEM32\samcli.dll
LoadedModule[40]=C:\WINDOWS\SYSTEM32\MSACM32.dll
LoadedModule[41]=C:\WINDOWS\SYSTEM32\VERSION.dll
LoadedModule[42]=C:\WINDOWS\SYSTEM32\USERENV.dll
LoadedModule[43]=C:\WINDOWS\SYSTEM32\dwmapi.dll
LoadedModule[44]=C:\WINDOWS\SYSTEM32\urlmon.dll
LoadedModule[45]=C:\WINDOWS\SYSTEM32\WINMMBASE.dll
LoadedModule[46]=C:\WINDOWS\SYSTEM32\iertutil.dll
LoadedModule[47]=C:\WINDOWS\System32\IMM32.DLL
LoadedModule[48]=C:\WINDOWS\System32\WS2_32.dll
LoadedModule[49]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\Common.dll
LoadedModule[50]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\DALib.dll
LoadedModule[51]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\Movie.dll
LoadedModule[52]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\DACOM.dll
LoadedModule[53]=C:\WINDOWS\SYSTEM32\DINPUT8.dll
LoadedModule[54]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\ImeUI.dll
LoadedModule[55]=C:\WINDOWS\SYSTEM32\SHFOLDER.dll
LoadedModule[56]=C:\WINDOWS\SYSTEM32\MSVCP60.dll
LoadedModule[57]=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\zlib.dll
LoadedModule[58]=C:\WINDOWS\SYSTEM32\MSVFW32.dll
LoadedModule[59]=C:\WINDOWS\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_5.82.15063.413_none_55bc94a37c2a2854\COMCTL32.dll
LoadedModule[60]=C:\WINDOWS\SYSTEM32\CRTDLL.dll
LoadedModule[61]=C:\WINDOWS\System32\clbcatq.dll
State[0].Key=Transport.DoneStage1
State[0].Value=1
FriendlyEventName=Fonctionnement arrêté
ConsentKey=APPCRASH
AppName=Freelancer
AppPath=C:\Program Files (x86)\Microsoft Games\Freelancer\EXE\Freelancer.exe
NsPartner=windows
NsGroup=windows8
ApplicationIdentity=9FA1EB2D2621C4363033D891BE983497
MetadataHash=-589977725

After quite a lot of trial-and-errors, I managed to run Freelancer in a Windows XP VM on VirtualBox, on a Windows 10 Host.
With an i7 4700 HQ laptop with 8 Go RAM, it runs with maxed graphic options.

Here is what I did:

1. Follow this excellent article to install your Windows XP virtual machine:
   http://www.makeuseof.com/tag/download-windows-xp-for-free-and-legally-straight-from-microsoft-si/
   I allocated 1024 Mo RAM, a Video Memory of 128 Mo and enabled 2D/3D acceleration.
2. Using the VM’s Peripherals menu, install the Guest Additions CD image and reboot
3. Install Freelancer (from CD or ISO)
4. Install the No-CD Exe : http://the-starport.net/freelancer/download/visit.php?cid=1&lid=2649
5. Reboot the WinXP WM, and press F8 to enter the “mode sans echec” (failsafe mode ??)
6. Restart the Guest Additions and select Direct3D (maybe this could be done the first time)
   [ I had added in the flconfig file : Vendor = 0x80EE “Virtual”
   0xbeef = “default”, but I don’t think it is needed at all]
7. Now, FL runs (even though it displays a large green block in the intro videos - don’t worry, no problem in game).
8. The mouse “jumps” 10% of the screen at each move -> disable Mouse Integration (VM icon on the bottom right of the window), this is solved.
9. Set the resolution in FL options before switching to Full Screen.

Et voilà, I could at last (re-)play this fantastic game !
Hope this can help others.
I have just to find a WinXP activation key to avoid having to reinstall the whole thing each 30 days…