The extended settings mod probably does not work because the patch to fix the signal bars affects some of the same files the extended settings patches do. It is probably doable, but it would take somebody that understands the extended settings patch to go through and look at what needs to be changed or moved in the files that have changed w/ the signal bar patch.
I don't know why China keeps changing these things so much on a code branch that they are doing very little to. Development work on GB from China has definitely slowed as they have started focusing on their ICS v4. The same fix from 2.2.10 does not work on 2.2.17. I haven't had a chance to go through and look at everything to see if it can be modified to work.
As far as wifi tether apps, I don't know what may or may not work on this build since I know longer have service to test that type of functionality. The only way to know for sure is to try it.