You're asking all the right questions, so your obviously a little worried about this car, and rightly so especially if it takes your entire budget. Here's what I would do.....
Tell the guy that you really want that car and are prepared to pay the asking price, but you have some concerns. It sounds a little rattly, so you would like him to at least change the
and the filter, if not do a full service (up to you if you want to splash out on a service for your new car) and see how it sounds after. As your a little worried about the stick movement, ask him to put it through an mot (you don't have to wait until it's due). If he's reluctant, walk away but leave him your number.