So I've finally decided to be a bit more selective about my flying habits in order to reap the benefits of a frequent flyer programme. I need some help choosing one so if anyone can provide some feedback that would be great.

I usually do one or two longhaul trips a year with up to half a dozen shorthaul and I'm based out of Dublin. Most of my longhaul trips are to Singapore, KL and Bangkok and sometimes trans-Atlantic. I know Aer Lingus have signed up Etihad as a partner for flights to the Far East but I find their FFP to be quite poor in terms of earnings potential, I might be wrong so please educate me on this one. I'm leaning towards United MileagePlus because:
- their miles don't expire once there is frequent travel.
- you can earn United miles on some Aer Lingus flights.
- I am most likely to choose between Swiss, Turkish, Lufthansa, EVA, Singapore and Thai to SE Asia (probably in that order), all fellow Star carriers.

Is this a reasonable choice given my criteria? Are there any drawbacks to choosing an airline that isn't even based on the same continent as me? Should I go with another alliance/airline?