Have just had a quick google for Ivybridge, and it has a population of 12,000 not 20,000, but as you can see it has a large youth population
http://www.ivybridge.gov.uk/community/
I also didn't mention that it is only a few miles from beaches, is almost on the edge of Dartmoor, and has Longtimber woods, which is great for walks.
I did find Devon quite remote though, it is a long way from anywhere! Liverpool is nearer to London than Plymouth is! When I left our house it took me an hour to drive to the 'Welcome to Somerset' sign, and you aren't really anywhere then! You don't have any large shopping malls, the nearest one is in Bristol which is an hour and a half to two hours drive away. And if you enjoy going to concerts or jetting off to foreign climes three times a year then you will find that you have to travel quite a way out of Devon to do this.
I did enjoy living in Devon, beautiful countryside, gorgeous beaches, lovely market towns to shop in, but there are down sides, the remoteness, the weather (it rains a lot in Devon - that's why it's so green! - and not much snow in winter if you like that). Also it can be an 'insular' place, which can be a good thing or a bad thing, depending on your view point! I knew people there that could count on one hand that number of times that had left Devon and Cornwall!
I think you need to book a few days there, and go round looking at places not as you would as if you were on holiday, but as potential places to live.
Good luck.