I just learned of your being blocked by twitter & the reasons why, and saw your request for suggestions. Here's mine
I have written about the excellent service you provide, and have designated you as my follower management tool of choice.
My suggestion is to go to a read-only mode and to do it quickly so that your wonderful service will be available again.
You will still be able to provide the filtering and the locking, which are the features that make your service unique and valuable.
I usually don't even use you for the actual unfollowing, because I have no way of discerning if someone might be on lists of mine; once I decide to unfollow someone I remove them from lists as well, but twitter -- for some dumb reason -- doesn't give you that option. So usually when I'm using your service to figure out who to unfollow, I click on the link to the twitter.com interface to see if they are on any lists. Sometimes I unfollow there, sometimes I unfollow back on your page, but it's really not important.
What is important is:
1. the good interface
2. the reasonable amount of time to load
3. the great filters
4. the locking feature
So please, go to read-only format, and do it soon. We need you.