God, I have no idea. You take Rainier's Willis Wall, I think it's probably not all that hard, but extremely dangerous. I would say the hardest part of Willis wall may be finding a reasonable way to go through the hanging glacier near the summit. The same would probably go for Liberty Wall.
I don't think so. Ptarmigan Ridge may be a little harder than LR, but not as hard, or not nearly as dangerous as Willis Wall. I know someone who has done Ptarmigan Ridge, and he didn't make a fuss about it. It had gone pretty casual for them. Willis Wall and Liberty Wall are a in a different league all together.