Well, I'll throw in my 2 cents.
I'm in favor of DIY tire changes, I think with practice most people can do it
You can't really expect to do it with a screwdriver.
I got a fairly cheap set of 3 tire irons (I guess $15-$20). They seem to do the job.
e.g.
http://www.bikebandit.com/manuals-tools/motorcycle-tools/motorcycle-tire-repa...(These might be the ones I got, if not something similar.)
I have changed all my own tires since I got the bike in 07. That was my first tire change other than bicycle.
+1 on a big piece of corrugated cardboard under you
+1 on dish soap for lube
I feel pretty ok about patching a tube.
I usually pinched holes in them and had to re-do for the first couple changes. If I had a new tube, I'd use it, but if not I'd patch.
I think I put 3 patches on one tube; I KNOW i've had 2 patches on a tube. Never had a problem.
I follow the directions on the patch kit, after it sets, pump it up pretty fat and check for leaks with soapy water; it'll bubble up if there's a leak - you can't miss it.
If you don't check your tire pressure regularly, at least do so for a few days after changing.
I line the valve stem up with the dot on the tire, seems to work ok. If it's unbalanced, it's not enough I can tell.
(I'm going to have to look into that rubber mallet method mentioned above, I know nothing about that...)