Whips are absolutely bonkers right now, yeah. They deal only blunt damage, and they have a surface area of 1, and a huge velocity multiplier. So, yeah, they're lightsabers. That's partly to do with the fact the game doesn't know how to simulate flexible objects, so a "whip" is 100% rigid with no give whatsoever, transferring all of its energy into the target on impact. Denser materials make them even more lethal, but an iron whip is still something you dont want in your opponent's hands, so I always try to disarm lashers and prioritize them and ranged weapon users. Your best defense is going to be a shield (or two. Or twelve, the game really doesnt care if you 'r'emove them form your bag after picking them up and then hold onto them indefinitely, and each shield counts towards a chance to block an attack.) I'd suggest getting one copper shield, and a bunch of wooden shields (because material doesnt matter AT ALL for shields' chance to block. Even blocking dragon fire). Copper shields are nice and heavy and good for smacking people in the face, and wooden shields are light so they dont weigh you down so much.
A morning star's edged attack is as effective as a hammer's (same surface area and velocity multiplier) with a little extra penetration, which probably won't be that important, so I suppose which one you want to use would best be determined by your skill with them.
You can wield any weapon in one hand if the other is occupied. In adventure mode, the game just doesn't care what your hands are doing.
And yes, kesperan, your adventurer's brain-nomming shenanigans are legendary. Poor Bora...