Well I can answer one of those for you for sure, having spoken to my Daughter ( who, as you know, works for the Border force on the other side of the Channel ). Despite my wish to leave the EU, I'll be honest and tell you that she told me it would be " Chaos " as far as Calais / Dover is concerned. ALL border force personnel would be brought out of France back to this side, where the checks would be carried out. The tourists could be checked, similar to airport checks, where passports, Visas & the like are checked. The difference is, in airports, we are on foot when going through passport control........these tourists etc. will have vehicles to contend with. The main problem will be the Freight ( on which most illegal immigrants get in ) hundreds of lorries will have to be stacked / parked, while checks are carried out. NOW all illegal immigrants found will be on British soil and their applications for asylum will ALL have to be processed HERE, they'll have to be held somewhere; while that process runs its course and the unsuccessful ones will have to be deported..........as they can't even deport the hundreds waiting to be deported already, that might be a problem. The same kind of border controls will have to be put in place, in every major Port in the Country and on the border with Scotland ( if they hold another referendum for independence and win )..........otherwise illegal immigrants could get into Scotland and then cross the border into England.

There, that answers one of your questions ( about borders )..........I bet your happy now........not !!