Regarding your crashing problem, try downloading this fix:
http://www.lucasforums.com/showthread.php?t=205145
As far as the headgear thing goes, that's what a disguise is supposed to do: it replaces what the character looks like and nothing else. So a mask should normally be seen even if there is a disguise equipped. If you don't want to see your headgear, then there is another mod for that.