I'm not a fan of youth models, even adjustable as kids outgrew them pretty fast. That's just a personal preference. I like the short/small but adult rifles. I started my son on my Marlin model 75, which is a very short small semi-auto, but at Christmas he had his own Henry. Very short, light rifle, but yet at 20, he still shoots it today, and does not feel like he's still carrying a child's gun.
Though I started him on what I had, I was happy to get away from the semi-auto a few months later. My beef has nothing to do with rapid fire, or shooting a whole magazine, but just about how much more complicated it is for a beginner of the basic safety functions of clearing an verifying a clear chamber in a tube fed .22 auto. Most .22's do not lock open like a pistol, and you can't simply drop the mag, and pull open the slide to clear it. While I also learned that tube magazines are not the greatest for beginners (though most seem to be tube)either, at least with a bolt or lever gun, they can easily lock open the action and at least clear the chamber without having to empty the gun. With the semi, after you chamber the first round, if for any reason you don't want to fire them all, you have to pop loose the magazine tube, pull the bolt back and flip the round out, and then make sure another doesn't go in when you let the action close, while holding the rifle in one hand, pointed in a safe direction, and performing the other functions with your other hand. A bit much for many beginners, and balancing even a small rifle one handed is tough for a lot of kids.