Anyone experienced in modifying this plugin?

Hello,
We have this plugin installed and really like it, but we have questions about its implementation.

1. When someone registers to ask/answer a question, it seems to force them to set up as a user on our site. Is there another way to do this? We’d like to not have random people be users on our main site.
2. is it possible to remove the Tag option? It does not seem to be working correctly.

Thank you in advance for any pointers. We’d also like to make a connection with someone who is very used to working with this plugin and who knows how to modify the pages, etc.
Niall.