Is 9 1/2 months too early to be transitioning to only 1 nap in the day?
He's likely not ready to be on only one nap per day yet, but he's definitely showing the signs that he's starting to transition and that may be part of the reason he's waking at night too. Have a read though this link and let us know what you think...
From 2 to 1 nap transition (10-12m and older).
Is he sleeping for 2h-2h15 in the morning? I'd start capping that to 2hr max, and then doing a second nap 4hr later for 45min-1hr. Something like this...
Wake 7am
Nap 1 10:30-12:30pm
Nap 2 4:30-5:15pm
BT 8/8:15pm
As for the NWs, at this age with my DS, I ended up having to go into his room and just sitting or lying on the floor and patting the mattress to have him lie down on his own and go back to sleep. He was having a lot of NWs where I would go in, lay him down, say my sleepy phrase and walk out. It turns out that my going in there and lying him down had become a prop of sorts. Once I had him do it himself (it took awhile the first few nights, at least an hr), after a few days he was sleeping through.
I think working on both of these things will help. Let us know what you think!