Trying to do a spiced pumpkin ale as your second attempt at homebrewing seems pretty ambitious. I can understand you might be anxious to forge your own path, but this is fairly complex. If you are still determined, though, I do have a few thoughts...
You didn't mention what yeast you are using, but I assume this is based on some other base beer? Or - is this based on some other pumpkin beer recipe? What made you decide on these particular ingredients?
Adding the pumpkin to the boil will make a big mess in the brew kettle. Be prepared for that.
There is no point in mashing just cara/crystal grains (there are no enzymes for conversion). You should just steep them. If you want to mash the pumpkin, you should do so with some base malt (6-row would be ideal) to provide enzymes needed for conversion. That will take longer than the 30 minutes you noted.
As to adding the spices to the boil - keep in mind that once added, they cannot be removed. I tend to make a strong "tea" with spices, and add to taste after fermentation and prior to bottling or kegging. That way you can control the final flavor. In either case, for cinnamon, it's better to use the sticks than the ground version - a little goes a long way and too much will not only be overpowering, but will make your beer "hot".