Of course if black blunders badly, white may have a chance. But if he doesn't, then black will just have a big advantage. For example, if Richard123 played 6... Rf8 instead of 6... Ng4?? he would just be up a piece for a pawn. Or like you said, if David played 12... Qxd1 13. Raxd1 Ng6 he would be ok.
If you like such gambits, I think the Halloween Gambit is much more serious and more "sound" than this. You probably know the site, but if you don't, http://www.jakob.at/steffen/halloween/index.html contains alot of analysis on that gambit.
For the past few months, I have been experimenting with the Jerome Gambit. The opening moves are 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ which is probably a dubious or blunder type of move. But it's the type of opening I like in blitz chess and I have had fun and success with it. My success this year has been 18 wins, 1 draw, and 1 loss. I got motivated with the opening after reading Rick Kennedy's blog site called JeromeGambit (http://jeromegambit.blogspot.com/) and after receiving a database of thousands of Jerome Gambit games that Kennedy has collected over the years. So I started experimenting with it in 15 minute games here at chess.com and other sites.
Here are a few samples of my games with the Jerome Gambit, named after Alonzo Wheeler Jerome, who experimented with it in the 19th century.
From Rick Kennedy, which I agree:
WARNING: The Jerome Gambit is quite disreputable and has quite a few refutations. Its use should be restricted to "fun" games or as a manner of offering "odds" to weaker opponents. The author is not responsible for any disasters that might come from using the Jerome Gambit (although he remains interested in learning about and staring at the wreckage).