I'd say it depends how tight your budget is. Elements can do everything you list, the full Photoshop obviously does more... if it was me and I could get the full version for $200 (not likely in the UK!) I'd probably go for that, but for the kind of stuff you mention it depends if the difference is worth the extra to you.
I believe you can download trials of both to try out though, so maybe you should head over to Adobe.com and give both a whirl.
I used to have photochop LE and it could only save in one file format. I would definitely recommend checking to see if it has a limitation such as that before buying.
I have heard that there are workarounds for most functions of regular vs elements, but that was CS2 or 3 and not necessarily the current version.
Elements is a lot more full-featured than you might think... I can only think of a few things offhand that CS4 can do that Elements can't. And Elements' panorama abilities are something that CS4 *can't* do.
If you are at college, consider buying Adobe CS4 Master Suite (Acrobat Pro, Dreamweaver, Fireworks, Flash, Illustrator, InDesign, Photoshop). Earlier this year I picked it up at educational discount for $595 (US).