I wouldn't trust it. An app just misbehaving can trash important parts of your filesystem. Suid root is just a bad idea, windows being linux aware or not. Just for mild amusement I think someone being funky got a windows virus to work under wine if I recall correctly.
Sure. Don't have to be funky - I've got Bagel from an infected Windows drive before just by running a program I had installed there.
rm ~/.wine -rf cleaned it up. I dunno if it was actually able to relay spam, or whatever it was designed to do, but it launched itself from an infected binary OK, dumped a copy of itself in c:\windows\system and then sat in the background. Thing is, it wouldn't have done anything different if I was running as root.
Anyway, interesting as this is, if we can't or shouldn't renice apps to a higher priority then we're back at square one. Are there any recommended ways of debugging scheduling problems Con, any tools we can use, or is it all down to guesswork and printf() timings?