I'm sorry, quote was too long. I just meant to refer to your new building and, in general, coping with users' doing unpredictable things in the network.

No class / offices / labs make things easier.

But still, most of our problems came (come) from residents and their personal laptops.

Our machines are configured so that is it ahrd for a user to create issues, and that proved good so far.

We are seriously considering Packeteer. So far we did not need to invest there and simple QoS worked well enough most cases, but we are adding more residential space (going up to 220 residents, plus 200 non-residents, plus offices), and personally I think it is very likely we'll end up with more trouble.
In an ideal world, I'd get packeteer and upgrade data link to 30 Mbps.