dreams - if you really want to move down here I think you can make it work but by the sounds of it the only sensible places for you to move would be Truro or Falmouth, or Redruth (only 30 mins drive from Truro and Falmouth). The main school in Truro is excellent, its just all the other schools that are bad!!! Nurseries around Truro and Falmouth seem good on the whole, have just been looking into them for my own dd, so I wouldn't worry there. And looking forward to the distant future, there is a very good college in Truro and the university of cornwall is currently being set up so by the time your son is old enough, he won't be forced to go miles out of the county for a decent uni.
Do you mind me asking what sort of work your dp would be looking for, then I can give you a slightly better idea of whats available.
Truro isn't very 'pretty' because its the business part of Cornwall but Falmouth is gorgeous and its only 30 mins from Truro, and that only goes up to about 50 mins in rush hour so its not too bad a commute. There's also a very good train service between Falmouth and Truro if you don't drive/don't want to drive.
The local health system is very sympathetic if you want to have a homebirth but if I was having another baby I would honestly move to Plymouth for a couple of months just to be able to avoid the hospital down here. I did have a fairly unusual experience because I had to stay in for 2 weeks because dd had jaundice and strep B but I've spoken to loads of people who've had babies there and had a terrible time, and there's been a few articles in the paper about bad birth experiences there. Saying that, they have an excellent SCBU unit there if there's anything drastically wrong - its just the main maternity ward that's rubbish. Its not 3rd world standard or anything but you have to know exactly what's what because they literally do not know their arses from their elbows.
Not trying to scare you off - on the whole Cornwall is a very nice place to live and day-to-day life isn't THAT bad, you just have to be very organised to cope with it!!