I was thinking yesterday about the same thing. It is strange that your ruler isn't leading (or an expectation that he does lead) your armies automatically, like in CK1 and CK2. Now you have to make him the army leader, but if you don't (so your ruler stays at home during war) then that isn't a problem with other characters at all. Just imagine, William the Conquerer not being present at Hastings, but back home in Normandy, while his troops fight for the English crown, that is just weird.
Something similar with Crusades, AFAIK as long as you sent your army it is OK by the Pope, you just place in him in command at the target to get him the Crusader trait and then replace him again.
Something similar with Crusades, AFAIK as long as you sent your army it is OK by the Pope, you just place in him in command at the target to get him the Crusader trait and then replace him again.