1. Not sure, I can't really remember ZoE 1
2. Jehuty in a stomp, Zero Shift and all the other powerful weapons at it's arsenal, LP goes down. Plus Naked Jehuty was cannibalistic, and would probably take some chunks of of Prime by biting it.
Liberty Prime issues forth manly phrases rendering paralyzed permanently.
Jehuty seems much much more manueverable. I'm not sure exactly how powerful LP's eye canons are but they destroy anything in the fallout universe in only one shot and I've never seen them miss. Also LP throws nukes like footballs. That's gotta count for something