For dropping your primary during Last Request, that is completely fine, you don't have to be in an active lr with the prisoner or be warden, you can order it as a normal guard as long as it doesn't interfere with the LR (a noscope battle for example).
As for commands that are related to getting to markers and movement commands, I'm fairly certain that these are not allowed during lr as it is the prisoners last request, and they shouldn't really be limited besides for the purpose of rebelling (like dropping a gun).