[magno]

You will need to get some kind of headphone amp to use headphones with your interface.
You're stuck with soloing the track you want to record effects on unless you use the S/PDIF outs.
Just a possible alternative instead of getting a new interface, you could look for a used t.c.electronics M-ONE cheap, or something similar. You'll gain 2 inputs/outputs on your interface get some cool effects to play with and you'll be able to patch any of you other effects in to it/bypass the t.c. effects, and not have to solo your track when you want to add effects.