On the squirt gun issue, an additional suggestion. Our squirt bottle is always in a fairly handy place, which means it's more than visible to any visitors. It now displays a prominently Sharpie'd "Bad Kitty!" label plus a crude drawing of a frowning cat. It's a quick explanation as to why there's always a bottle around, and gives visitors a quick chuckle.
Our tabby is built like offensive lineman, so we failed on a few budget scratching posts that wouldn't support his shall-we-say ample frame. We ended up spending an uncomfortable amount on a better post: http://www.amazon.com/SmartCat-3832-Ult ... ching+post
(Actually the price has gone down substantially). I'd highly recommend this. It's heavy and stout and has a durable scratchable surface. It's still going strong after about 2 years of heavy use by 2 cats.
While the animals are learning the rules, you can always add packaging tape to the corners of furniture (assuming they're only interested in the corners). Rigging it with a sticky side out if you want to be doubly cautious, but even the single sided stuff is unsatisfying enough to keep them away.
An inconvenience is only an adventure wrongly considered; an adventure is an inconvenience rightly considered. -- GK Chesterton