Bishops in the Rat Defense

I've been looking at this line: 1. d4 d6, 2. e4 Nf6, 3. Nc3 g6 (in the Game Explorer), and am puzzled about the next White move. Let's assume we have to move a Bishop. Yes, I know there are other choices, but that's not the point now. 

I have 2 questions... 

There are 10 possible Bishop moves, 2 of them being suicidal and therefore irrelevant. What I don't understand is this:

1) Why have 2 (4. Bd2 and 4. Bb5) of the 8 non-suicidal Bishop moves never been played (according to the Game Explorer)? Or rather, my question should be: what's wrong with these 2 moves? 

2) Of the 6 Bishop moves played in this line, one of them (4. Bd3) gives Black a win ratio of almost 4 (White won in 21.4 % of the games, Black in 78.6). What's so horrible about this move? 

I hope some of you more experienced players can explain this to me. Thanks! :)

I'm probably not who you had in mind, but here goes:

1. Bd2 isn't good because it blocks the queen's view of the d-file for no good reason. As for Bb5, well, is that move as useful as Black's reply of ...Nbd7?

2. The high scoring for Black doesn't mean much by itself given the small sample size. However, I don't think Bd3 is such a good move; it just begs for Black to play ...e5.

Thanks a lot, khpa21! I was exactly explanations like that I was hoping for! Thanks!