HeavyG -- I once created a half(red)-dragon/troll with one level of fighter for a Smackdown type of battle; I wanted to see if I could create a CR12+CR8 encounter that would beat the pants off of a group of five powergamed min-maxed CR12 guys.
It worked

. "Barney" the half-dragon troll Fight1 had a pixie/Wiz1 with a scroll of AM Field that he carried around in his backpack, and a 7th level cleric buddy with the Magic sphere who had some scrolls of Solid Fog.
Can you say "Instant Death"? I knew you could.
Barney was a 32-point buy character with a 13Int, 12Dex, and 36Str. His claw/claw/Rend damage averaged about 60pts, as I recall. And in the AM Field, he was pretty much auto-hitting. And NOTHING was touching him; he had a non-magical AC of 32, 37 if he used Expertise. Try hitting that as a 12th level character with NO magic.
His only problem was catching the party, but the Solid Fog (no save, no SR) solved that problem quickly. He'd get close, swing, Snatch (dragon feat), and win the grapple check (duh). Next round, he'd let go as a free action, claw, claw, bite, rend, and then use one of the claws to Snatch once again.
Basically, he was doing about 75pts of damage/round, automatically, and he was almost impossible to hit -- hell, he was just about impossible to get away from.
Ahhhh. That was a fun . . . and quick . . . combat. I think they managed to do six points of damage to him.
However, when I bought Barney's stuff, I didn't give him gold for a 12th level character. I basically gave him the amount of gold it would take to get from 10th level to 12th level (30k or so).
Anyway, I know just how cheaty this proposed character was. But take away the AM Field and the Solid Fogs, and you've got a character that's a bit easier to handle -- through spells requiring Will saves, and just pure beatdown. If you can find something willing to risk the claw/claw/rend every round . . .
One other thing -- making him a Red Dragon instead of Gold would solve the weirdness problem (though then there might be an alignment problem).