Franz can not DM for combat

A lot of the combat just doesn’t work like it’s supposed to. When it’s a rogue NPC’s turn, with a finesse weapon (finesse = you can choose if str or dex is used) he automatically picks strength, even if dex is the obvious choice. Or when I tried to to hit a structure with my hammer, while my party members were fighting, it was impossible to do that as an action. Franz made a creature named “structure“ that also attacked me on it’s turns.
Or I once tried to do a 1v1 against one of my party members and all of the other party member just automatically jumped in. I then tell Franz that it’s a 1v1 and that he should remove the other party member, he says he’ll skip their turns. Only problem is that he doesn’t do that.
I really like this entire concept btw, I just thought it would maybe help if I talked about the small amount of problems I do have. Keep up the good work!