Alright, I've been having trouble saying what I think in screenshots, so I hope you can interpret text instead.
BLU Spawn
I think you should restructure BLU's spawn to be a bit more convenient to navigate. Right now it's 2 very boring corridors that lead to 2 doorways next to reach other for both points. One of the cool things about Gravelpit is how there are multiple drop offs from BLU spawn that are far enough apart to give BLU choices as to where they go in the battlefield, and keep RED on their toes
A
I don't think A is an interesting point. It's just a building with a deathpit in front of it. You should scrap A and replace it with a more varied area that doesn't rely on a deathpit to add difficulty to it's capture
B
B is the overall better point between A and B, but it still has a few glaring issues. First off, the point building can be camped like hell. I think adding a soft counter to sentries would improve attacking the point dramatically. I also think you should move the point back a bit, it's a VERY short walk from BLU spawn to B's point, and that makes it a bit too claustrophobic for RED to defend without spam. Mainly I recommend improving the areas around B, and doing something to reduce camping within the point building
The Tower (New C)
I know that the old C from A2 is gonna be put down, so I'll give feedback on the prospective spot of the new point. I think you should have the point itself at the bottom of the tower. Focus combat around the upper levels. If BLU wants to cap, they have to clear out the heights above, and if RED wants to keep the point, they have to kick BLU away from their vantage points. Also, add some more space around the point, and generally make it a bit harder to reach the tower itself.
Okay, that's about all I have to say about A2. I think this map has a good future ahead as long as you can work off the feedback people give you.