I also used two of the big Libby cans for mine. I put my spices in at flameout. I used 0.15oz of cinnamon and it think it was a tad too much. But I had doubled what i planned to use because on brew day I discovered we were out of allspice.
I didn't roast my pumpkin. And I put mine in with the mash.
I think as long as you keep away from strongly flavored hops, you'll be fine. You want them to complement the spices, not clash with them.
The only thing worse than someone who whistles a tune is someone who whistles tunelessly.