It'll be fine. To be honest, I've made em with pumpkin in the mash, pumpkin in the boil, and one that I called a pumpkin ale and I didn't even add pumpkin..... They all tasted close to the same.
The spices will change during fermentation, and begin to mellow somewhat over time. What kind, and how much spice is a delicate balance and will be a personal preference. I tend to use about 1/2 of what a recipe calls for (I don't care for overwhelming spice), but I brew at least one a year full tilt as I have friends and relatives that LOVE the be big spice kick.