Well done. With the evident understanding your writeup displays, what I can't figure out is why your blitz rating is still below 1000. I'm sure it won't be for long.
Why do so many people use this opening?

interesting that you say a lot of players use this gambit...im not familiar with it and havenever come accross it, though.
my gut reaction is to say that...you shouldnt worry about this sacrifice too much. white's strong light colored bishop vs black's right to castle...sounds dangerous for black. except that the sacrifice seem pre-mature. white doesnt have enough pieces developed to take advantage of black's weak king postion. the danger is real for black, though, and he has to develop quickly to take advantage of white's momentary weakness.
white's idea, i think, is to launch an attack against black's weak f7 square (the board's weakest point) and weaken black's king position. but you usually want the light colored bishop to successfully exploit this square. or if you sacrifice this bishop, you should already have a back up force to make it up for its absence. otherwise, white cannot justfiy the sacrifice. to sacrifice material, you have to be prepared to attack aggressively. and to sacrifice your strong bishop, you have to have a very aggressive attack already ready to go.
i think that for white, after 5. ... Nf6, he should play 6. d3 to solidify his center and give his remaining bishop direct sight of black's king side. or bring out his king's knight and plan on getting it on the g5 square to put pressure again on the f7 square. the knight move also prepares for castling, which brings the rook to bear again on the f7 square. however, this is move 6 and he's still just mustering his forces together. the sacrifice happened 3 moves previously. i think this is just too slow.
for black...after 6. Qb3+, i think its better to play 6. ... d4 blocking the threat, taking over the center (which will make it hard for white's queenside pieces to get over to the other side of the board and join the attack), and freeing up the light colored bishop (which, in the absence of its white counterpart, is now very strong). w/ both black bishop's now exerting active influence on the game, he can start thinking of launching his own counter attack on white's own uncastled king.
Hey all :D
In some of my recent games, people have tried playing this opening against me (Shown below). My problem with it is it puts you down material early in the game, the position is easily defended once you activate your queenside bishop, and both pawns can be pushed up to protect the king and a rook easily finds an open file. Why do people play this? Is there a different line that top players use that provides more threats and damage?
Thanks! :D