btw i don't even know now which users i should remove from my trust list and which could stay in (i don't see any difference)
Don't include people in your trust list because they have dealt with you and you can trust them with money. This deserves a feedback.
When you leave accurate feedback in your perspective, only include them in your trust list. If they leave wrong feedback, exclude them from trust list.
For reference, LoyceV guide is the best-
https://bitcointalk.org/index.php?topic=5191802.0