Hi Jim
to Cable Forum, I hope we can help you out
1. You only need the drivers installed if you connect via USB, if you connect via ethernet to a network card, you don't need them. Ethernet is by far the preferred method of connection.
2. They can get quite hot, but are designed to be on 24/7 so if adequately ventilated, should be ok. Don't think you'll need a fan though
3. I have my SACM on tp of my pc, with no problems, however I wouldn't advise putting the router on top of the modem.
hth