Is there any way to reduce the general MUI memory consumption? I haven't actually customized anything, leaving all of the options at their default values, no background pics at all, I have only changed the default fonts... Any tips?
There is nothing to do about it. It is not only MUI but also newer MUI programs need more ram than old MUI programs. I used to browse internet on vanilla A1200 (only 2MB, Miami 1.0, IBrowse 1.0 :-P) but without images of course.
You could disable image/webpage caching to ram in browsers, it maybe helps a little.