Just on the DUB-GLA/PIK thing, just look at DUB-EDI with both, FR moving to GLA will have some affect but nohing much. FR are 3 or 4 daily DUB-EDI in the summer and its down to 2 at times during the peak. EI are 5 daily, and they have business friednely tmes. FR have a 6.30 ish, 12.30 ish and 22.00 ish flights to EDI, a move to GLA would be the exact same while EI's tomes are much more favourable at 6.30, 10.00, 13.00, 15.00, 18.00 (not exact times).
One thing I did note FR have knocked 5 euro off PIK fares and EI have not cut them unlike other UK places where FR followed EI.
In gernal any move to GLA or even fees deal with BAA will put a lot of noses out of joint and could be a big mistake for BAA, unlike EDI GLA has a vey large bucket and spade market and FR flooding it with there low fares won't end well.