Here's the analysis:
https://www.chess.com/analysis?tab=review
Tricks only so not too bad in blitz or rapid but would not recommend playing it too often. Eventually, people will learn how to deal with it and you will be stuck with a bad position
A team mate of mine ~2030 ELO, play this. It suits his style and gets decent results, but I suspect it may falter against 2200 plus players...
Yes and no. 6... Nc6/Nf6/e6 is essentially already winning for Black. 6... c6 is kind of an unintuitive plan. I play something similar against the Caro-Kann, but at worst you're only -.8 (depth 30 SF 15+ NNUE), whereas in this Scandi after any decent move after accepting the gambit and Qa5, you're anywhere from -1.6 to -1.8 (depth 28 SF 15+ NNUE). I much prefer my Nf3 Be2 d4 c4 d5 0-0 setup.
I never knew this had a name. I think its about as respectable as the Scandi, which is to say I'm not a huge fan of either. It is hard to argue that it would not be effective though if one's goal was simply to raise their rating (below a certain ELO). I can't imagine >50% of your opponents would know 5) ....Na6 in the line. Anyone trying to get better at chess should just develop as normal though... d4, etc.
I love this line. I know it as the Mieses-Kotrc gambit. I used to play it all the time in blitz. Now I'm getting too old and sluggish for blitz, so I play it in rapid. I think it's considered a pretty suspect line, bordering on unsound. But it's fun in fast time controls.
I find this line of the Scandinavian Defense intriguing since it starts off with a very appealing pawn sacrifice, and it's basically over for black after accepting the gambit.