Funny you should mention Ray Mears. Though, living in the US, I haven't been able to watch his show, I have heard a LOT about him, and he is a greatly admired figure amongst wilderness survival/bushcraft enthusiasts. I love that his idea of a good bushcraft knife is a Mora, too. That's common sense. Which is a rarety these days, and something Bear Grylls is quite short on.
Nope, and I never will, I hope. I don't carry knives for self-defense, I carry them as tools. I'd much rather have a walking stick for self-defense, as A) It has a longer reach; B) It can get the job done just as well without unnecessary bloodshed; and C) It looks a lot better to the authorities in this age of 'political correctness'.
That's a good question, Petrie. Balisongs (butterfly knives) are indeed illegal in many states. In some states, it is legal to own them, but not legal to carry them. In certain states, though, they are perfectly legal.
After a bit of research, it doesn't appear that they are directly referred to in Illinois law. However, a knife with a blade at least 3 inches in length is considered a 'dangerous weapon' in Illinois law. Since there is no direct mention of balisongs/butterfly knives, they may or may not be legal, it would depend on the police officer/judge. But a balisong with a blade under 3" would not only be more difficult to manipulate, but harder to find.
Would you be just using it around the house, or would you want to carry it? Also, be warned, if you are going to be practicing balisong tricks, etc, you WILL get cut, possibly seriously. A link to state knife laws: http://pweb.netcom.com/~brlevine/sta-law.htm
Is it a liner-lock or a lockback? Locking Mechanisms
I find liner-locks easy to close with one hand, but then I most likely have larger hands than you do. You may find a knife with an Axis lock to your likings, they are easily closed with one hand. For example the Benchmade Griptilian, a great knife. Or a non-locking Swiss Army knife.
Most outdoors knives do lock, and in my opinion this is a good thing. It makes the knife usable for more things, safely. As I mentioned earlier, I myself carry both a liner-lock (a Benchmade Vex) and a Swiss Army knife (a Wenger Handyman) daily. I like the saw on my Swiss Army knife, it comes in handy in the woods often.
Edit: Sorry about the last two paragraphs' being underlined, I can't seem to fix it. Something with one of the links messed it up.