Here's yet another thought on this.

Perhaps the way to get around the issue of sorting the forums is to minimize the number of forums that are displayed in the first place. One option is to use sub forums. You can display the main forums and also have related forums grouped together in a sub forum. I'm assuming that the last post date of a thread in a forum of a sub forum would be displayed in the main forum page, but I'm not sure. A list of possible groups may be:

Tips
Disabilites
Q and A
Couples
Using KSMO with other practices

Not every forum will fit nicely into a group so having a Miscellaneous or Other may work, but that would tend to hide them without a more descriptive title.

Another technique may be to combine forums. The groups I mentioned above (plus others that we can think of) could possibly be combined with each group being a forum. So, you could have just a Q and A forum, a Disabilities Forum, etc.

Just some thoughts. Hopefully these are helpful.

Otp