We live in the Tamar Valley near Gunnislake and love it. Good choice of schools and pretty good transport links for Cornwall. (We are also selling a house we inherited in the region if you are interested!)
My DH is from the region and we moved back here because he got a job here over 20 years ago now. Within 2 years the firm closed and so he was doing the weekend commute since then. He would either drive to Exeter (50 minutes) and train it, or drive to Basingstoke which is about 3-4 hours. There is also the new train link from Okehampton to Exeter too.
I don't know the villages you mention that well, and like a PP wouldn't really think to visit them. They are quite rural and distances round here can be deceptive, with somewhere that is closer may take longer to get to. Also I know some village down here are at risk of losing their village school due to falling numbers.
I think 'backward' is the wrong word for North Devon but it is a very poor and disadvantaged area (there was a piece by Alice Thomson in the Times about it) I always feel I've gone back in time every time I go north of the A30. I was really shocked last time I went to Biddeford, you could see it was once a charming town but it was so run down it looked with lots of empty shops, gangs of bored teens everywhere. However, that was about 6 years ago now.
It can be difficult in areas like this because when you live here all the time you don't want somewhere too much of a holiday destination, which is empty in winter.
If it's at all feasible I would think about living here for a bit before you decide where to put down roots.