Regarding the SVN problem: My suggestion is to start the SVN server, check each repo out with git SVN brigde (e.g. Tortoisegit has it integrated right into the clone dialog) and then upload it as a git repo. You can have the full history from SVN this way. You just need to do this correctly. I have some SVN repos checked out as git repo just before it got shut down this way. But not all of them.

No problem

Wenn du etwas neues erstellen willst (eine neue Mod) dann solltest du vermutlich das SDK verwenden (dafür ist es da). Wenn du die HD Edition verwendest (also eine bestehende Mod) dann solltest du erst einmal um Erlaubnis fragen ob du diese Mod überhaupt für deine Zwecke verwenden darfst. Ganz speziell wenn du deine eigene Mod veröffentlichen willst, wäre es ratsam die Erlaubnis zu haben, wenn du Werke von anderen Moddern verwendest (immerhin haben diese Zeit und Arbeit in diese Mods gesteckt).

\Freelancer\FLARDATA\Textures
should be the folder structure

inside you have the PBR texture folders e.g. NormalMaps
Creating normal maps would be the starting point, Metalness and Roughness maps later on if you need them. HeightMaps would be a special case that you wont need that often actually.
Create the DDS files and put them into the folders using the original texture names that you can find via UTF. If you work based on original tga textures don’t forget to flip the texture before storing them as dds.
Normalmaps need to be stored as ATI2 and all others as ATI1 dds. Overwrite textures can be dxt1-5.
You dont need to manually edit the material file (but you can). You can use the ingame dev menu to set roughness and metalness values. These values get stored inside the material config file.
I personally edit the material config manually once I know the settings. This way I can group textures which have similar settings and keep everything lightweight that way.

You’ll also need to install FL Patch 1.1.