I think you just do the search with the page open with all the forums listed below, I will call it the forum page as the homepage is something different altogether.
Edit;
Whoops, I didn't see the search button was missing there.
That's only there if you click the "new posts" at the top (which is a pre-formed search). If you just enter the forum window directly there is no search function. The forum used to have a search text bar along with the magnifying glass item on the same row as the "new posts...mark forums read" line.
Reputation. You can add reputation by clicking the little star icon under someone's post. I don't think anyone has ever used it, because it's dumb. :lol It's always been available, just may not have shown the dots if you'd never received rep.