I've driven 3 out of the 4 of those. Quite different sizes; the Focus and Jazz are a different segment to the Mazda 2. The 2 is really fun! The Jazz I found sluggish and weird, like driving a mini-bus, but it's not my style of car at all (there's no oomph and it could never been described as sporty) and I didn't really like it. The Focus is a good all-rounder; you can fit a lot in them, they handle well and there's plenty of room. 1.6L gives just enough power in the Focus; any less and you're not going anywhere, but I'm basing this on a Mk I in which I commuted 120 miles a day some years ago.

You're right to rule out diesel; there's no point on short trips like that. I'm wondering if some sort of hybrid wouldn't be the best for you but you're not going to get one for £5k I don't think. You could add the Mazda 3, which is Focus-sized. A Toyota Yaris might do you very nicely but it won't be as zippy as the Mazda 2.

I agree with the suggestion that you try a Yaris - go for the 1.3. My daughter had four of them in succession and found them quite zippy. The Yaris has sold better than the Mazda 2 so there will be more to choose from. But the 2 is a good car as well.

The Swift is probably more fun than either, if you are within range of a dealer.

You are 42 and don't want feel old driving the jazz? I shall say im 24 when i own my jazz. drive it 2-3 years never given me any major problems. The practical of jazz simply beats its class even better then size of car like golf. i remember thats the only supermini which can fit 2 proper size bicycle with a mid range size piano in the same time. one time i even fit a full size elliptical in it. ride is not comfortable but still it is very economical. Already missing it, since i now dont need to move around sold it and get a new polo, much more refine but no where economical and pratical as jazz. forgot about swift and jazz if u want to move stuff around, the boot is hopeless!