MikroTik

Does anyone have an Idea on how I can do a little bit of user uptime accounting and have MT disable clients automatically when they get to their limits?

Better still is there any AAA software outside freeradius? I'm not a linux person.

You must have another mashine for Freeradius, with BSD or Linux OS on it.

install freeradius on linux machine
check the attributes in the dictionary file of mikrotik
or install alepo ... rodopi.... on windows machine