There is no such thing as an accurate poll. The only poll that gives a correct result is the actual vote itself. Until then, no one can really tell, as we have seen at least twice in the recent history (*cough*Trump*cough*).

Yes, there are different polls. The results differ depending on who does them and when. Just like the first time, the polls swing almost daily.

52/48 or 46/54 makes too little a difference. Should the second vote go in favour of Remain with such a small margin, Leave will never accept it and call immediately for best 2 out of 3. The only real difference would be if the rerun showed a really decisive result, like 70/30 or more. But that is not going to happen.