#1 Member renews membership and pays online. Everything goes through fine but he is not automatically enabled.
If you're using PayPal it sounds like IPNs are not configured correctly or return data is not enabled for PDT. Please review the CBSubs documentation for PayPal configuration instructions.
#2 the member is getting multiple emails for "your membership has expired" and "thanks for renewing"?
I can't see any reason for this unless you've setup multiple CBSubs Mailer emails that overlap or you've setup the Presentation emails in addition to CBSubs Emails.
#3 when the admin renews from the back end they get an error message. moscomprofiler::store failed: Unknown column 'receive_htmml' in 'field list' SQL+UPDATE 'xvkl1_comprofiler' SET
Something is trying to modify the receive_htmml column in CBs database table, but it doesn't exist. Maybe an invalid CBSubs Field usage or CBSubs SQL Actions? It could also be an invalid CB Auto Actions usage of a Field or Query action. If none of those then something third party is doing it. Check Joomla authentication and user plugins since it's happening on login.