Passport thing is pretty standard as employers can get prosecuted if they employ people without the right to work in UK. So they take a photocopy and bung it in file to prove they are checking. I think usually it is a case of - oh, standard UK issue, and don't look. I think the agism comes in at the CV stage though...
And there have been times, one recent, where a manager expressed doubt that someone around 60 would stay long. I usually point out that they should match applicants to the person spec. and that plenty of people these days work until they are in their late 60s.or beyond.
Good luck with the new job.