Are we able to have a maternity photoshoot there?

I would guess so, ask a professional photographer

Last time i was there i saw 2 separate photo shoots. One of them was even using lights

I've seen wedding photos being taken there. I'd call and ask first, but im sure it's perfectly fine.

Yes, its a very relaxed place. We took countless photos. I assume as long as you don't dominate an area for too long, making other guests unable to see the displays, you'll be fine.

Yes

I think so.

Yes definitely