Hi Brian,
I was moving completed requests to "Completed Support" and found your post. Sorry it got lost in the mix and didn't receive a reply!
If I have a list with people subscribed to a series of followup msgs and I want them to receive my regular emails as well, do I just email to the same list?
Yes, you can click "Send Email" to send email to your list(s) or selection(s) alongside your regular followup messages.
And is there a way without customization to have those who finish the followup series automatically moved to another list?
Not yet. In recent versions there are now options for "Loop followups" and "Load Followup Set" but not "Move to List". This is an excellent suggestion for a future release!
Regards