Take nothng to heart, as if you want to fly I know you will (we were all in the same position once), but it may be a struggle!
1. Low- very little sponsorship in the UK at the moment at all, let alone for someone who has no right to work here, and is unlikely to get it until trained. Aus, same problems plus be aware that you pay for the training still over there!
2. G.A. flying is not a starter career, that is a common misconception. Most need 1000-1500 hours minimum, as an inflexible requirement laid on them by their insurers. To go that route you will need to build lots of hours, perhaps instructing, but that's another rating to achieve! (about £6000 (perhaps US$8500) in the UK). The airlines are the starter career!
I don't know the state of the dispatcher market.
3. The CAA no longer issue national commercial licences. Assuming the ATO is under ICAO the JAA course is reduced, however you will still need toe 14 groundschool passes (tough even with 6 months instruction, I teach the course) an initial IRT (tough) and enough UK flying to persuade someone to employ you. And a work permit. At a time when we may still have too many pilots (though I do not think so).
If it is your dream, best of luck!