Firstly if you get a shark, any species, the tank needs to be set up just for the shark. Most if not all need hiding places, can't have any metal of any kind in the tank, need super high filtration and great water quality, and any tankmates can be considered dinner.
Alex, I have worked in a public zoo and there is a good difference between raising, say, a tiger cub to adulthood and keeping a tiger in captivity and releasing it as an adult. Reputable zoos and other wildlife parks do not keep up the handraising: there comes a time when you no longer directly interact with the animal because of the danger it poses to the animal's future as well as any injury possibility to the keepers.
You can't do this with a shark. More specifically, you cannot keep a shark in captivity, in a controlled environment with steady food and diet and then release the shark when it no longer fits in your aquarium. The shark will die. It won't be used to the new water, to avoiding other predators or certain prey---it may not even recognize natural prey as that. If nothing else there is a huge risk with pathogens: a shark raised and kept in a captive environment has no chance to build up its immune system from standard bacteria found in the wild and not in a tank.
I get the feeling you will do what you want regardless because you are so certain that one more animal kept in a poor environment means little in the grand scheme of things and, well, goshdarnit you want an effing shark. Who are we to tell you it's a bad idea, other than people who have walked down the same path you mean to travel? If someone tells you not to stray off the paved road, there are zombies in the woods, will you weigh the risks, decide you want to do it anyway, and become zombie food because you want to be that variable to see if living in a zombie-fested woods is possible?
Yes, in the past and even now people keep many animals that have no business being captive pets, lions, tigers, chimps, sharks. But if we don't learn from past mistakes, why should we not repeat them? It used to be seen as weird to get your dog or cat neutered, and in some areas it still is, but that is no reason not to fix them.
You want a shark that stays very small but looks like a 'real' shark and if you want a live fish, it does not exist.