A few questions regarding AROS

[Argo]

I think you'll be stuck with UAE for running classic apps. That is unless UAE can be/will be integrated into AROS.
AROS is not an emulator, but a reimplimentation of AmigaOS and its APIs. Programs have to be recompiled to run under AROS due to the under lying hardware architecture difference.
It's basically the same for Amiga OS 4.0 and Morphos. The only reason they can run classic apps is their integrated classic emulation.

Check out : www.aros.org

aros-exec.org would also be a good site to look at. Though I can't seem to get there at the moment.