This is a tough topic because I can see it both ways, but you know the old saying:
"Absolute power corrupts absolutely".
This is certainly true in a car with the power of the Mustang. Eventually, you'll just have to put your foot in it...
However, I don't think it's so much the speeding and racing that is the problem necessarily (although they are major contributors). It's that the V8 has lots of power that can get you into trouble on ice, snow, wet roads or in avoidance situations with other vehicles. The inexperience of a 16 year old driver and the power of a V8 just aren't a good combination. The rearend can break away just too easily... then you're in a world of trouble.
I know that Bad_intentions has said he has been driving since 13, but I'm talking about REAL driving experience. The kind you get with years of driving on freeways, at night, day, on all road conditions, alone and with friends, etc. Getting a shot behind the wheel every once in a while coming home from dinner with mom and dad doesn't count.
Sorry, I feel for you Bad, but it's true. Take the V6, make some mods, and trade it in 2 or 3 years for a GT when you go to college, or leave home. That's a far better deal than most of us have probably had at your age (Slow97 notwithstanding
).