subforum display, yes, if I follow you… this is group view right? then add a stack=1 argument to the sp_ForumIndexSubForums(); template tag call in the group view theme template file for the theme you are using…
so for the default theme, would be
sp_ForumIndexSubForums('stack=1', __sp('Sub-Forums'), __sp('Browse topics in %NAME%'));
as we recommend, dont actually modify one of our themes, copy one and create your own theme so its safe on updates…
BrandonC just started this code entry, but it should help creating a theme:
http://codex.simple-press.com/codex/themes/creating-a-theme/
our documentation for 5.0 is just beginning, so you will have to bear with us for a while until we get it up to snuff…