Ok, off to BCN for the weekend and very much looking forward to it as it is one of my favourite cities. However I am dreading the return journey as every time I have departed through BCN it has been a complete 'mare

I have a couple of questions - any regulars able to help me smoothe the trip this time? ^
1) BA check-in is in Terminal B. However last time the queues for security here were horrific and, once I cleared it, I was mightily pi**ed off to have to walk the entire length of the building back into Terminal A which seems to be where the non-Schengen flights depart.
So, the key question is, can I/am I better off to go through security at Terminal A since I will have PYOBPed and have hand luggage only.
2) Where the hell is the BA/IB lounge??? I know it's crap, from what I have read on here, but I would at least like to find it. Last time the extremely rude woman at check-in told me it was by the departure gate. So I went through the Schengen exit passport control, presented myself at the lounge on the other side only to be told that it wasn't the BA lounge at all and I should have stayed the other side of passport control? Anyone know where it is?
Thanks in advance!