My only serious problem with firefox is that a single tab can lock up the entire application. Otherwise, the performance _and_ memory usage is fantastic. But that one issue is enough to keep me away from it most of the time.
In the meantime, you can test more tab processes by increasing the "dom.ipc.processCount" pref in about:config. I set my process count limit to 999. :)
The UI said it was due to accessibility features.
Is there a timeline for getting it working with touch screens or has that already happened?