You might get lucky and be granted access to fast-track as a Gold, or it might be a "computer says no" day (usually an excuse to do with biometric security). Either way security in T1 never has really bad queues and you should be through in a few minutes. Fast track is to the right of the main security entrance beside the Boots beside the United / TAM / SAA checkin. Fast track is usually superfast!

After security enjoy the shops and restaurants, of which there are lots. As DUB is within the common travel area it leaves from the domestic area. You need to pass through a further biometric check point to reach this area, and there can be a bit of a queue here if there are lots of EI flights about! Don't go through this checkpoint if you want to shop as you can't return and the only shopping beyond is WH Smith and Costa.

Once in the domestic wing you can sample the delights of the BA Lounge, previously known as the London Room. Drinks and crisps and soup and that's really it, though plenty of space and quiet.

If you're really lucky your flight will board from gate 8, immediately beside the lounge, otherwise it's a 5 minute hike out to gates 76-84 in the green mile!

Arriving 60-90 min preflight is plenty of time, wouldn't as you need much more than this.