I don't know what you mean by responsive, but it doesn't get very hot at all. It gets warm when I play a game on it, but not bad. Over all, I love it. It gets about 5 hours when fully charged and works fast. There's one thing that bothers me, and it's that the scrolly thing on the pad doesn't work anymore. I don't know if I changed a setting without realizing it because it worked the first day I had it. Hope that helps a bit :)
Yes. Any Windows 7 computer can do so via the input/mouse options within the control panel. You can also configure it to automatically be disabled if a mouse if plugged in and functional when the mouse is unplugged.
I would say the consequences are quite small. You're talking a second or milliseconds. IMO the 8gb of RAM is more important. I also prefer Windows 7 over Windows 8 This laptop is plenty sufficient for everyday use for the price. It is not a gaming laptop by any means. I highly recommend it. Plus, whatever computer/laptop you purchase, within 6 months there will always be something better. That is the nature of computer evolution.