What are your thoughts on the queens gambit declined: Austrian variation?

It's absolutely playable. Especially if white underestimates it and tries to punish black.

O'Kelly used it for many years to make a draw. He got the variations from Rubinstein (who loved symmetry and direct action in the centre), with whom he often analysed.

These days Mamedyarov specialises in the move.

unplayable, White gains an undeniable advantage if he remembers a short sequence of forced moves, of course even Mamedyarov, its main supporter, doesn't play it now because it's simply bad

How does this short sequence of forced moves you speak of go?

White appears to score too high in databases. I prefer playing 2...e6 first followed by 3...c5 (Tarrasch Defense), white's scoring is reduced at least somewhat then. 

Depends on what you mean by "now".

Sounds interesting, I’ll try that next time someone plays the queens gambit

"Double Queen's Gambit" according to Russian GM Bezgodov, who wrote a book on it 7 years ago. It's entirely playable, but not THAT easy to handle as Black in the main line 3.cxd5 Qxd5(!) 4.Nf3 cxd4 5.Nc3 Qa5 6.Nxd4.

I do prefer the Tarrasch approach though, especially since it was discovered that Black can avoid the annoying dxc5 line using the "bad" move order 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nf6!? which was discarded since ages due to 5.Bg5. However, after the audacious 5...Be6! Black has a decent game.

#4 3. cxd5 Nf6 4. e4 Nxe4 5. dxc5 Qa5 6. Bd2 Nxd2 7. Qxd2 Qxc5 8. Nc3 and of course the Black position is horrible with Rc1 and Nb5 coming next

You talked about forced moves, and then you missed the first departure: 3...Qxd5.

That's an integral ingredient of a good confusion.