31 queries for a vb2 index page is really not basic...
iirc basic was 15 queries.
as for showthread, 33 queries can be ok, it depends if these are fast ones or not, i'd suggest to remove some though...
Maybe you have just some hacks which are not well coded.
sometimes you can combine a few queries (take a look at my forumhome optimization for vb2, or a quite similar hack by filburt.)
there are some optimization hacks for vb2 which i suggest to install, or the much better way:
upgrade to vb3