Yes they do. If your checks don’t come back satisfactory then they contact you and tell you but won’t give you any more information which is wonderfully helpful...
Yes they do these take about 2 weeks if I remember rightly.
Yes they do a full DBS screening before considering you a candidate for interview.
Yes, crb and employment background checks
Its takes a month and they do, based on previous jobs
It took me around 1 month and then I had to work 1 months notice
Yes, they take quite a long time because they ignore most of the information given to them