Brakes
Since your front wheel doesn't move (unless you are using rollers, but I would stay away from those - especially if you will let your kids use it - you need very good balance to use rollers, but a stationary trainer holds the bike steady- you need no balance at all) you can squeeze the front brake all you want. I don't think I'd really want to use the rear brake - the unit that you are turning with the rear wheel that is usually pretty heavy and using your brakes with it instead of just letting the resistance stop the wheel
might be damaging to the tire if you do it a lot. Better to just let the resistance stop the tire, it won't spin much at all if you stop pedaling. I don't think once you get back out on the road you will forget to use your brakes
Setup
Depends on the trainer, but on most models that I've seen putting the bike in and out is pretty easy. Mine (a Cyleops) and I think many other brands, have two thick metal tubes that go over the skewer on your rear wheel -you will need to replace your rear skewer with a metal one if yours is plastic - it only costs about $7 for a metal skewer. So you position the rear wheel so that the left side is set in and then there is a little lever or a screw down handle that moves the tube on the right side in to lock on to the other side the skewer. Then you tighten down the resistance unit until its touching the wheel tight enough to not slip. The whole set up takes probably about 30 seconds to set up and less time to tear down.
Tires
Knobbies and slicks refer to the treads on the tire - knobbies- usually mt bike/hybrid or cyclecross tires have deep treads for riding in muddy/rocky conditions and slicks- like on your road bike have no or very little tread.
Effort
As far as 1 hr on the trainer being worth 2. I have agree that trainer time is harder than road time. I don't know if its 2 to 1, but if you think about road riding - you get to coast sometimes, you stop for lights or stop signs, you get to go downhill. On a trainer its kind of like going slightly uphill the whole time without ever stopping - and there is no breeze. I need a fan when I use the trainer and I still drip sweat all over the floor even though I'm set up in the basement where it is colder and only wear shorts and a sleeveless top.