great chess opening?

The line you gave is the Queen's Gambit (by transposition)  Black can now play c6 and get into a Slav/Semi-Slav or e6 and get into a QGD/ Semi-Slav. Except Black will have more choices now and you will have less due to the early e3.

However, there are much better ways of getting to this position since the line you gave eliminates quite a few options (by blocking in the bishop). Instead I suggest you use this move order:

By using this move order, you have more choices. The QG is theory-heavy but for this opening ideas are more important imo. So if you want to learn the theory, make sure you know the ideas for this opening first (and obviously opening rules too)

Hope this helped

Oh and by the way, in the QGA, you WILL get your pawn back since black can't really hold on to it and be ok:

It's fine, it's just a transposition into the queens gambit that doesn't have a name.  The only problem with it is that you can't play Bg5 or Bf4, which are both pretty spiffy moves.  If you are really afraid of black holding onto c4 (...) then go ahead, there are worse moves in chess. 

Not sure, it's still a Queen Pawn opening by naming standards. If you played Bd3 followed by c3, that would make it a stonewall attack.