I, too, am frustrated by some of the limitations of the search function. The developers of our forum software significantly reduced the usability of the search function when they released this new version of UBB.threads. I hope that someday we will have a better version. I don't agree with your complaint about the defaults (e.g. date range), however, since all of that is easily changed.

I use many forums that require registration before the full features can be used. Unfortunately, the sad fact is that the Internet is increasingly inhabited by people who do harm to places like this. We used to allow anonymous posting and less cumbersome registration procedures, until we got bitten more than once and finally had to change our forum settings.

The registration process includes email verification and manual approval, which is all explained on the registration page when you register for the forums. Reading that information can spare you a lot of frustration.