I actually really like the 1hp modifier but it makes the paladin even more useless
I really think the Paladin is the best class, but I can see why it would be really hard to solo him... actually it'd be pretty hard to solo any class but the ranger I'd think.
(at least in the full version) the paladin has a really high damage output because he can attack faster than the ranged classes can, and his sword swings in a large arc. He can buzz-saw most mobs before they can hurt him. The only tough ones to deal with are the elite ones that have more hitpoints than he can buzz through (like the beetles with spikes, or the grubs and skeletons with mohawks), against them you have to kite them (attack twice, back up, attack twice, back up).
Also, after a couple of upgrades, his dash is really high damage (since it is a multiplier of his basic attack).
In a 4-class, 4 player game, then yes, the ranger is going to be attacking all the time, looking like he's the most effective (although he can be kind of boring to play), then the wizard. The paladin is going to feel like he is sitting around not doing anything sometimes, but he's just trickier to play, you have to watch threat vectors, decide when it is time to go in and when to just draw fire away from your ranged buddies. With the dash and the speed of his basics, he can make some great assassination dives against generators.
I just wish spikes didn't insta-kill and instead just did some damage and pushed you off of them. It makes it hard to move across timed spike pits in 4-player if even one of your team is less-than-coordinated.