I would also like to see the a search button appearing more prominently in the individual forums, with the default behaviour when clicked on listing as "Search This Forum", not "Search Everywhere".
Looking at XF2 - when clicking the Search Bar in a forum, this seems to default to "Everywhere" as the main search option. In XF1 it looks like this defaults to "Search This Forum Only". At minimum it would be great to replicate the XF1 behaviour in XF2.