In reply to saturn:
Your first question is best answered by the BMC's regional Access database:
https://www.thebmc.co.uk/modules/RAD/
Access information from this is normally indicated on the corresponding crag page on UKC, on the find crag map page you can see if there are access difficulties based on the colour of pins on the map (green is generally good but may have some stipulation, orange is sensitive and/ or with stipulations and red is banned).
RE: bolting, check if there are routes already there, if there are Trad routes or bouldering problems you should generally leave the drill at home. If there are sport routes it may be acceptable with landowner permission. In England and Wales I would encourage attending a BMC area meeting and contacting the area chair beforehand to get the discussion included on the agenda.