Fa2fi
Has hit the nail on the head for commuting on SH if you are junior and full time. Everyone I know who is a commuter has or is just going 75%. A friend of mine had in the past been on the phone to me almost in tears because he could not cope. The strain was pulling his family apart and he was in no state of mind to fly so had to take a few days off. The guys flying 75% seem to cope much better because they can always ensure some family time each month.
Max drift: I would apply and go for it. If you get through then you have some serious talking to do with the family. I would have reservations about commuting but if you want a fresh start then it could be for you. Once an hour or so outside of London house prices really do drop off and lifestyle improves. The BA package is good by industry standards in the UK and with 30 odd years to go I thing you would be throwing a career option away for short term comfort.