sometimes Halloween but the most likely answer is Thanksgiving
Typically on Thanksgiving (late November) but also for Christmas holidays.
The stem
If it is eaten in large amounts or eaten with a big meal, yes.
The inside. The seeds can be toasted and eaten like sunflower seeds. They are quite tasty.
pumpkins
yes, I've bought and eaten it.
The bugs will invade and the pumpkin, and maybe the vine, will be eaten/rot away.
Pumpkins are eaten year around, usually as pumpkin pie (a popular thanksgiving dish) & pumpkin bread. I have seen recepies for pumpkin soup and other dishes.
I'm probably guessing that pumpkin seeds are eaten up by animals such as deer, moose, etc. Then later on, they deposit the seeds via feces, then they grow.
Yes, carving pumpkins can be eaten, but they are not as flavorful as other types of pumpkins. To prepare a carving pumpkin for consumption, you can roast or bake it, make it into a soup, or use it in recipes like pumpkin bread or muffins.
Corn, pumpkin, squash, and beans were some of the crops grown and eaten in Colonial Connecticut. They also ate a variety of seafood and turkey meat.
Depends on the celebration, but lamb is a popular dish in general. Different regions have different customs and popular foods. So what you have in a celebration depends on the local customs.