I love the whole concept and I had a lot of fun playing the map. As I could only play with bots, I just wanted to point out some things.
Point A feels too close to Blu Spawn and if the Blue team manages to completely wipe out Red team, they cap the point too fast.
The straightaway tunnel between Point A and Point B could use some cover to prevent anyone coming that way from getting bogged down. Just a few crates to provide some simple cover would be good.
When playing with bots, the Engineers will deploy sentries right outside of spawn. I don't know how skilled you are with bots and programming, but that's something.
Overall, I understand that you're still working on it and you've got other things going on, but those are some improvements I wanted to share. I can't wait to see it when it's completely finished!