I'm pretty sure you can use Trish to get the Bloody Palace achievements. Which is a plus, considering it's the easiest with her.
Does DMC2 have "super" characters?
Yeah Trish is fine for BP.
No Super characters.
On a side note, worst boss fight ever made goes to Tateobesu, the fucking fish in Lucia's mode. In DMD it STAYS invisible for the entire battle which means no lock on. You're pretty much completely blind. Absolutely fucking annoying.