These moves look less-than-best to me, along with possibly better options:
2...Nf6 (e6, etc.)
3...Bg4 (e6, etc.)
Qb3 is almost always good against an early Bc8 development in the QGD. The pattern shows up in a lot of openings - Bishop develops, and opposing Queen moves in the other direction to attack the Knight pawn. Qb3 vs. Bf5/g4, Qg4 vs. Bb4/c5, Qg5 vs. Bc4/b5, and Qb6 vs. Bf4/g5.