I'm not real sure what you're getting at when you say

Failure of the truck? or just individual items that commonly fail?

In general it sounds to me like you are interested in preventive maintenance, not a "rebuild" as some seem to suggest. I think its kinda dumb to simply start throwing parts at something just because they are a certain age. It would be much better to do a thorough inspection to see what actually needs replacing. A lot of it will depend on how and where you drive it, and how much.

yes, the things listed are some good things to check. Other things would be stuff that is on the 30/60/90k maintenance list in the owner's manual. Its actually pretty thorough. You could also do a compression and leak down check on the engine if you wanted to get a better idea of its overall condition. Search this forum and the FAQ for other common problems like clutch brackets and starter contacts too.

And yes, I'd say its almost always more cost efficient to keep an older vehicle well maintained than to buy another one to replace it. Its just a matter of whether you want to deal with that maintenance or buy something newer that doesn't really need much maintenance. And frankly, I don't really think of a ~10 year old Toyota as very "old," myself, but like I said before, it really depends on what kind of life its lived in that time. California is generally a whole lot more kind to vehicles than a lot of other areas...