This website is really neat and you should check it out if you haven't already. It's translating a bunch of interviews and stuff about AA and we get little pieces of information, like how AAI was almost a dating sim, the VA for the protagonist in DGS spent an hour recording "Objection" and the creators ended up using the first one he recorded, and the director for AJ only got the job because he had a picture of him eating lunch with Takumi and even he doesn't know why.
This video gets a few of the highlights.