This isn't a suggestion, but positive feedback
Hope this ok to post this here.
Just wanted to say that the "Thank you" feature is a great idea. I've seen places that allow you to rate users in other ways, such as by the sheer number of posts made.
You have this feature, but limit to cute changes in people's titles that don't really pass judgment like others often do (because quantity of posts shouldn't be the only measure of a person's worth on a support site).
But the "Thank you" feature is a way of helping users boost their self-esteem w/o turning into a fierce competition that wouldn't do well in a support group environment while also providing users a simple way of thanking others for their input and support.
I just wanted to say that I think it was a good choice.