I would love this. UT99 has aged wonderfully (gameplay-wise, anyway) to this day, but getting it running on modern systems has always been a pain. Ironically, I've had better luck getting UT99 running under WINE in Linux than on Windows 7+.
No idea. Ran fine with no tweaks on 2006-era Fedora. (A pleasant surprise at that time, since that was the era of hand-editing XFree86 conf files to get multiple monitors to work...)
This wiki page suggests you'll need to install the old libraries it expects. https://wiki.debian.org/Games/UT99 I also assume the UI wouldn't scale correctly to the native resolution of hiDPI displays.
UI will fill whatever resolution you throw at it, but it won't autoscale. However, there's a checkbox somewhere in the settings there that enables 2x scaling.
