Thanks for the first answers to my questions Shrooblord.
My own trading post: I have set up two of these in different sectors. If I'm on the ground and sometimes kicking out an NPC dealer, they even make some money. If I leave the system, it is mostly over. Is it perhaps related to the fact that the trading post needs an enormous amount of storage space because nothing else is delivered? The default range is unfortunately not selectable and rather crap.
Factories / Mines: Here's the problem of one of my teammates. He founded it according to the requirements of a YT gameplay video and has not received any credit since leaving the sector. Only the personnel costs are billed regularly.
Fighters: I read about these MODs. Unfortunately, this is not my Avorion server and I can not try so if these MODs would fix the annoyance.
It is a bit annoying to have to bring additional carriers to work properly with the fighters.