phh1998

I wasn't able to find a thread for Dublin Airport connections, so feel free to move this post if there is one that I missed.

In a few months' time, I will be taking a BA LHR-DUB positioning flight followed shortly after by the first leg of a DUB-LHR-SAN ex-EU ticket.

I have booked the LHR-DUB leg on BA 838 (Dep. LHR 1715, Arr. DUB 1845), though thanks to BA's free Same Day Change policy for Club Europe, I should hopefully be able to change this on the day for free to an earlier flight if needed, provided there is seat availability.
The DUB-LHR leg is then on BA 829 (Dep. DUB 2035, Arr. LHR 2150), with the LHR-SAN leg to follow the next day in the afternoon.

I am travelling without bags and with fast track (it is a Club Europe ticket) for the LHR-DUB/DUB-LHR flights. Would the scheduled 1h50m self-connecting layover be sufficient? I am aware that T1 at DUB does not have a connecting facility, and connecting usually requires going out through immigration to landside then coming back in airside through security and immigration as a normal departing passanger.

Additionally, I am neither an EU nor a UK citizen (and thus likely unable to use any automated entry machines that DUB may have), and I was wondering whether that would result in long immigration queues during an evening DUB arrival from London?

Finally, I assume there is not but thought I should check just to make sure: I have absolutely no idea about Dublin Airport layout, but I was wondering if departures and arrivals for LON-DUB flights share the same floor due to the Common Travel Area? If so, is there any way I could just walk out of the gate, stay airside, then simply get back on my DUB-LHR flight in an hour or two without leaving airside?