BrentDC,
I can understand where are you coming from with your approach to TS v3 - we developers all love our stuff to be nice, neat and clean, don't we? Nonetheless, removing ability to add custom engines straight from UI renders your widget virtually useless to me, as I would never make my little microb.php engine script to your library of shared search engines. Secondly, it doesn't seem to be possible to add multiple instances of single search engine, like separate wikipedia searches for en and pl locales.

As you pointed, users can hack your app and make own search engines fairly easily, but that's not what users would rather expect. I hope you could reconsider keeping at least the most basic UI for adding own engines. I need to tell that wizard present in v2 was slightly confusing, personally I'd expect only one field, like "Search engine URL" with example value of "http://www.google.com?q={query}" and that's it.

Btw, you say you need to spend 10-15 minutes to create an engine? So you add them manually? Or you have some sort of webservice that TS is using to download engines?