I would love to have a lot of unbiased and specific information on this 'problem'. I'm not sure where it would come from though because even the sincerest poster will be getting some of their information from sources which have an agenda and/or a personal bias.
Some people have described that they feel they are in hostile territory and any moment will have to run for their lives. I think the implication that the UK government might start rounding up jews is ridiculous. If people really think like that then I'd expect their dealings with non-jews to be wary and uncomfortable for both sides. Perhaps some of the 'subtle' anti-semitism is actually just that discomfort showing through. I would certainly avoid the company of someone with that attitude.
As for the anecdotes they sound unpleasant indeed, but how many cases of open abuse have there been and how many of those were anti-semitism and how many simple bullying/nastiness.
Take the attacks on cemetaries. Our local cemetary is always getting vandalised by drunks and kids and that is just vandalism.
If the same people do the same thing to jewish graves then it is counted as anti-semitism? Sometimes it might be, but you'd expect as many cases of ordinary vandalism as anywhere else yes? The anti-semitic attacks would have to be in addition to the 'normal' ones.
Some posters are including as evidence the opposition to the current Israeli government. That is an entirely different thing. The attempt to class all opposition as anti-semitism is not making them any friends since it's so transparent an excuse.
There will be people in this country who have lost family to the Israeli attacks (and vice versa) for them it will be personal, but their attitudes don't prove a wider problem on their own.