I think the fees are pretty much the same wherever you choose to go, or at least I haven't found any differences. They might even be the same across England, but if not, they are only a couple hundred quid apart at most. Since you're from the EU, you'd be paying home fees, anyway, and I think they're in the range of £3,000 - 3,500. Be sure to check out their policies for second degree students, though. Manchester, for example, implemented one this year that states such students have to pay fees that international students' rates, which is a lot, and, in my opinion, not worth it, because you've got so many other universities on the same level without such policies. Though, of course, other universities could start doing the same thing, but I kind of doubt it, I think this is more of a "we're Manchester and we're aiming to be at the top with Oxbridge, so we can afford this kind of stuff" mentality
I'll let other people answer your second question, but, personally, I didn't even consider doing a BSc, but only an MPhys. From what I could tell, it's formally an undergraduate degree, but it "feels" and gives you the knowledge of a Masters one. But I'm not really sure how the implementation of the Bologna system impacted the UK, and I'm not studying there, so I can only guess. I've been told you can do a PhD after a MPhys, and possibly even after a BSc, though I guess not a lot of people get in then. And if you want to go abroad, I doubt they would take you in with only a BSc (except perhaps the US), as it's common practice in other countries to do a bachelors, Masters and doctorate without skipping the Masters. I come from an EU country, as well, and that's how it's done (t)here anyway (although, again, it's a bit weird now, since a bachelors degree usually took 4 years, but they had to trim it down to 3 years due to the Bologna process - now people that are getting Masters degrees are actually only on par with those that got a bachelors degree in the old system). And I've looked up some CV's from people that made it to MIT and such, and they had a Masters degree, too, even though they went to the US. Which, if you think about it, is kind of weird, because studying anywhere in the EU, a BSc will give you more Physics knowledge than a BSc in the US will. But eh, I digress. Still, I'd recommend doing a MPhys, it's only one additional year, but I bet the knowledge you get adds up to more than that and you're in a better position for a PhD (well, you're certainly not worse off than someone with a BSc).
Funding for EU students unfortunately isn't as good as for UK residents, because there's no bursary scheme that would take into account your finances. You can get a loan quite easily, but the amount you can get isn't that high (I think it's around £3,000 maximum, so if you don't have a lot of money, that's not going to help
that much, it's not a make-or-break kind of amount). I have a friend who studied in West Bromwhich, though, and said she didn't spend much more than she would've at home (and I don't come from one of the affluent European countries, such as Germany or France). Though take that with a pinch of salt, she had that cheap British grocery store chain right across her apartment, and you know how it is with girls, they don't eat much
Anyway, I stopped following the Euro-sterling exchange rate, but I think the UK is the most affordable English-speaking country to study in for an EU student right now. Unless you get a scholarship in the US, Canada or Australia, anyway.
But, again, I'm not studying in the UK, I'm in Canada right now, but this is the info I gathered this year when contemplating studying there.
