I agree ... Father-and-Son projects are great, but a 914 isn't the car to go with. When something breaks in a 914, it can sometimes cost ... a lot. Teens like to part with YOUR money, not theirs.
Teens are impatient; 914's require patience. Teens know-it-all; 914's are a learning curve. Teens are fashion and peer driven; 914's are 30-years-old and the fashionable rice cars aren't. Teens wanna boom-boom-boom anna zoom-zoom; 914's ... well ... only sit two.
As far as insurance is concerned, 914's are listed as "Porsche," NOT "VW," and 16-year-olds rip you a new one when it comes to liability rates as it is, let ALONE comp. & collision.
I enjoy my 914, and LOVE Porsches; my 4 grown sons own a '02 MINI Cooper, a '90 Miata, a '93 Celica GT, and a '94 Celica ST. They all started out with the best, HUMBLE, most reliable hand-me-down clunker(s)
I could afford (a VW Jetta, a Geo Metro, a Mazda 323, a Subaru GL).
The cars hauled their shoe-leather buddies, took them to their part-time jobs, and helped show their girlfriends (and after college, wives) a nice time with money left over.
Start 'em off small; fewer regrets.