[LMPego]

I don't know Cory's exact cage size - I'll see if I can find the dimensions online.
Cory was never a rough player as a baby, she'd rather cuddle and have me fix all her feathers for her.
We actually let Cory keep her flights after they grew out from her baby clip. I found it helped a lot with her shyness. She's still fearful of anything different, but now she feels like she has freedom to take herself away from the situation and I think it's made her a much better companion to have those choices. But, you have to look at your own situation to see if Jake would be safer flighted or clipped.
As far as roommates, I personally would never force 2 birds to live in the same cage unless they were already mates. Cory can be very aggressive with Zen. When we were looking for our second bird (Zen was our first), our vet told us that we should get the bird that we want because the 2 birds are either going to get along or they aren't and there's nothing you can do about it. I would put a second cage next to the first and if they choose to share a cage, then that's their decision.
I hope that helps.
I'll get back to you with the cage size.