Is it possible to somehow transfer a basic sbd actor pawn into the blender and edit it like for example give him extra arms?
This isn't possible to do with the editor program in SWRC. The editor has no export features for meshes, of course there may be some third party program somewhere that you could rip them out, but I doubt it.
Ok thanks.
you could use gildors unreal model viewer. you can extract ukx.(repcom's animationpackagefile) into psa.(animationfile) and psk.(modelfile) with it. then you import it to 3dsmax with an importer which is also made by gildor. but its pretty impossible to get it back to repcom.
so yeah, my suggestion: use accessoires. go to the actor browser, untick placeable classes only?, make a new subclass of accessory and add it in the default properties of the pawn.