userChrome file could resolve the UI thing, use something to have chromium interface

for performance, all that i could see is that profiles are ignored, both on chromium n firefox, i use a lot of profiles to minimize addons impact on performance, and with a lowend computer i always got a smooth xp on firefox

If create desktop doesn't work, u can always go to about:profiles and manage/open from there

dunno, but already changed to another search eng on mobile