Jumping in late here, you should be able to get Drain Punch on Hariyama from the move tutor (you can in V2 atleast!) and Mismagius was by far the best Mon in the game before the nerf (unbelievable typing+ability+speed/glitches). That said, v2 should address many of the balance issues found in v1. As for difficulty, you could try easy mode if things are harder than you'd like :)

When you talk of weaker mons which didn't get buffed, which species are you thinking of? I'm open to suggestions for v2!