unfortunately there are better options. much better ones. I dunno what yall using as a base but it needs help obviously. I know firsthand from last month from dreamhost alone that en-mass ddos and spamming happens and it breaks websites terribly. The other half is code optimization. If you do it right your site can have split-second interaction.
A lot of people prefer drupal (see facebook) or dreamhost, like myself and feathercoin staff. There are forum (bb) options as well. The trick is keeping alive site up and going thru database dumps when needed.If you arent using one, you should be. The half of this is having access like I do to the following:
Apache or nginx
SQL database(accessible only thru above)
and knowing how to manage(and backup) both.
As per site registration, when this breaks, nobody can register. And since all of the old postings for FP(C) got thrown here, we have nowhere else to post but our own blogs.And this has broken. I have been forced to wait years because of this to re-register after the forum switched. You can use hidden fields to detect bots just as well. Per post capchas are pointless waste of peoples time.