Absolutely. With the caveat that despite the misappropriation of the word, entities that do not mine are not 'nodes', by the original definition. That aside, you sum up pretty completely the reason that I run a fully-validating-wallet.
These are also the reasons why I run a full node, on a old core-duo PC in my basement, which I upgraded with a big hard disk, and at which I look once a month to see if it is still running. The other reason is to study the system itself. I actually don't use my full node as a wallet: I use a light wallet on another system, and I connect to my "empty" full node in those rare cases I use bitcoin to pay for something (once or twice a year, say).