I'm not a dentist, but from what I can see a torus would develop in order to support the jaw, like a structural reinforcement.
However, if it runs in the family then its likely the inherited mutant gene. At the same time, it could also be an inherited grinding trait.
If its grinding, your dentist will notice chipped teeth, flat back teeth, and the tops of your teeth will look faceted, like a gemstone. You'll also have damage near the root of your teeth, as thats where the tooth "bends". If thats the case, its time to buy a dental guard.
If thats not the case, then its just the inherited lumps and bumps.
As for piercing.... I personally wouldn't combine a subconscious tooth grinding habit with a bit of metal. Run it past your dentist if its the grinding thats causing torus development. Most dentists dont like tongue piercing as is... it tends to chip teeth, which is something you do NOT want if you already have problems with grinding.
If its not grinding, then as well as the usual health concerns, you have to consider if swelling of the tongue is going to affect your mouth. If those bumps already take up a bit of space, then a swollen tongue could be very hazardous. Swelling is fairly common as part of tongue piercing, and the presence of a bar moving around your mouth might agitate those lumps.
I can't tell you whether or not to go for it... I'm not into piercing at all so I might be biased that way, but imho if its just for cosmetic reasons then I'd really not bother. If you get your tooth grinding fixed then I'd certainly give it more consideration, and if the grinding is fixed AND there's plenty of space in the mouth then I'd give it as much thought as any other piercing.