This is one of those things that will give you 1 million opinions and possibly no "right" answers.
As for my thoughts, and that's all they are, it's no different than your kid at 14/15 and starting to learn to drive. Do you take them out on back country roads to practice and get the hours required for their temps or do you hide the keys from them?
Think about it. How many 15/16 year old kids steal their parents car b/c they never get to drive, don't know much about it, and are curious? Do we treat the car as we do guns? Nope. Keys are left where everyone in the house knows it and cars sit in the driveway just begging to be driven.
Pop quiz. What kills more people every year, including teens, cars or guns?
Knowledge is power. If you have your kids respect and you use common sense concerning safety guns in the house are perfectly safe. How many eons did houses have guns and 14 kids in 1 little cabin? Today is no different.
Just my .02 though.
EDIT: And FWIW I grew up in a house where dads gun cabinet, with a glass door, displayed his shotguns, pistol, and rifles. Guess what? He taught me right, taught me safety and functions of the guns at a young age, and I NEVER touched them or wanted too. I also never stole the car or went into their bedroom without permission.