free ESAT questions
Get ready for the ESAT with 379 high quality questions, all for free.

The real ESAT is scored with a Rasch model, a standard way of scoring tests that takes into account how hard each question is. ESATvault currently uses a custom score conversion table instead. Once enough people have used ESATvault, scores here will be calculated with a Rasch model too.
This depends entirely on the university and course. You can generally find statistics for each online from their websites or FOI requests. However, since a 4.5 is the average, you will want to aim for higher than that. 7.0 is the top 10%, so it is a strong score. But it doesn't really matter: you should aim for the highest score you can. (Note that no score "guarantees" an interview or offer.)
As soon as possible. But don't focus on it so much that it hinders your grades or predicted grades, since it is sort of expected that you have all A* for Oxbridge and Imperial.
I think the NSAA/ENGAA papers (earliest first) and the specimen/sample exams given by UAT UK are a good place to start, to get familiar with the format. Then you should start trying some harder questions which are closer to the actual difficulty, like TMUA and some other resources. I don't think it is necessary to force yourself to complete papers in the time limit at first, there's really no point. Speed is a by-product of getting good at the questions, so it comes later. (However, you should still record how long they take you, to see how you're getting on.) Once you get closer to your exam, start enforcing the time limit.
They are as accurate as I can get them. I have sat the ESAT twice, so I think I have a good understanding of what the questions are like. Some questions will be much harder than others though, so don't be discouraged if you are not getting them all.