If you have it running on the Mac already, you're likely already doing fine. I doubt you'd have any improved experience getting Mac to pretend to be straight Linux, only to then emulate Windows on Linux on Mac, rather than just emulating Windows on Mac.
Re UOA, In my experience, it is so unstable as to be unusable on Ubuntu. (I've found the same to be true for Razor, for free shards.)
Re: EC on linux, at least for me... running the AMD 64 bit kernel, some of the libs EC wants are less functional when installed using winetricks. EC will install for me, but it can't run successfully.
Re: the CC on linux, there are only really three things that can cause me problems. First, occasionally, the client will get stuck thinking a meta key (shift, alt, ctrl, menu, windows, etc) is pressed. This can make macros and such go wonky, though pressing and releasing each of the meta keys almost always clears the incorrect "pressed" status. Second, the client is horrible at memory management. Go somewhere with lots of items (well-decorated castles, etc), tons of mobs/special effects (event bosses), or the like for a few minutes, and the client will get really sluggish, including slow mouse control, while I can watch memory use just grow out of control in a process manager.
@Kyronix The final problem is the one that I most wish could be addressed. Full screen mode on my box is equivalent to "completely lock up the OS mode". I
never want it; it doesn't work on my box. But occasionally, the first bug here kicks in, and normal typing soon inadvertently means I accidentally hit the "switch to full screen mode" macro, and UO takes out my OS, requiring a reboot. I can turn off full-screen in uo.cfg, but that's just a saved state; it doesn't actually disable the mode. I would love a way to entirely disable full-screen altogether, so I can never accidentally trigger a switch to that mode.