I can't answer all of your questions, but I can help with a few.
First of all, generally speaking, there is absolutely nothing wrong with a 2007 Oasis. Obviously each individual boat has seen unique usage, and you want to make sure the boat doesn't look like it's been beat up or abused.
I wouldn't call the 2007 Oasis less seaworthy than the current model, probably less efficient, but we're talking minor differences. If you had the money to buy the newer one, it's the better boat, but that doesn't make the previous version a bad boat. Hobie still sells the Outback, and Outfitter which are the same generation of boat as the 2007 Oasis and have similarly designed hulls.
Safety is a tough question because safety is so heavily dependent on the user. In general, and for several reasons, I think the Hobie boats are among the safest boats on the market. The sit on top design allows water to splash over the hull, and instantly drain out, they are stable, and relatively hard to tip over, and they allow you to use both hands to grip the boat, instead of having to deal with a paddle.
Having said that, the safest boat is not safe for the dumbest user. So when you first head out, get comfortable with your boat in a safe area. As you gain experience, you'll begin to realize when conditions are very safe, and when conditions are not.
My wife is not a strong swimmer, but it didn't take her long to feel safe in 6 foot waves on Lake Ontario when she had her Revolution. The key is to find the balance between feeling safe, and being safe.
Feeling safe might mean that you're overconfident, and that can cause problems. If you pay attention to the dangers, you'll be able to develop an awareness of the concerns, and kayak in confidence in a wide variety of conditions.
As far as things breaking. The boat is made primarily of plastic. Plastic, and metal, and rubber, and ropes, all do break. Having said that Hobie's are very reliable. You need to be aware that things can go wrong, but at the same time, you should buy with confidence knowing that you have a well engineered boat, made with high quality materials.
I hope that helps a little bit. Someone else will have to help with your Santa Barbara questions, as I don't have local knowledge.