Sounds like you are trying to cover a lot of topics in one thread!
I don't see any problem with the use of hormones to regulate ovulation (i.e. the sponge) (it's no different to the human Pill really is it?). It's not an invasive procedure (having been for my smear test this morning I think a wee sponge is nothing!

), although I'm not so keen on using PMSG to bring ovulation forward when the animal was not already ovulating; I think you are just fighting nature then, which is never a good thing.
Synchronising breeding can improve welfare throughout pregnancy in terms of feeding appropriately, and at lambing, in terms of there being someone there to deal with any problems.
I don't agree with bringing on labour just for our own convenience.
I don't see a problem with AI where enormous genetic progress can be made in a short time in order to improve the health of the species, or to save rare breeds. I don' t know enough about AI to know the difference between invasive and non-invasive; obviously the less invasive the better

. Certainly we shouldn't be doing AI just for our own convenience, but as it's expensive I think ppl who use AI must have a good reason for it? It's been used for ages in pigs and cattle, although I don't know how the anatomy differs between them and sheep, I assume it's harder to AI sheep?
I'm not sure I see much difference in the motivations between AI and non AI breeding - commercial farmers are always going to try to breed an animal that will make them as much money as possible. The AI process just accelerates that programme. Whether they are breeding for the right traits is another matter, and not one that is restricted to the subject of AI.