As Moini mentioned, the filters were all re-arranged in 0.91. I don't specifically know of any that were just dropped. But I also have not gone through and tried to find them all either. Since we've had several messages about that, over the last few months, maybe I'll try to do that in the next few days?
Since I'm not a Mac user, I can't help with the Filter Editor. But maybe suv will be able to help you with that.
I think Tav....or was it someone else....who finally finished a tutorial on creating new filters, and I assume editing them. Let's see if I have a link.... Ok, here's Part 2, and Part 1 shouldn't be too far away:
http://tavmjong.free.fr/blog/?p=1516Edit
If you can show us specific files with specific filter issues, we'll be glad to try and solve the specific problems. But you've made some rather open-ended comments about filters and 0.91 in general, that make it hard for us to get started in any one place, to help you. Maybe I'll have a chance to locate where all the filters were re-organized. But for the issue with text vs area around text, we'll need specific files and filters to investigate.