There is a moderator bug in 3.05 but I am not sure if that is causing your problem. You can search the forums here http://xoopsforge.com/modules/newbb/viewforum.php?forum=1. There were a few posts dealing with the "mark topics read' issue. Hope that helps.
I can't help you with the redirect but the email sent upon user activated registration uses an email template located at root/language/english/mail_template/register.tpl
That is a bug and I'm not sure if it has been fixed. I went crazy trying to figure it out when I first installed Xoops. I still haven't seen any resolution on this but maybe you'll have better luck.