
No and No.
Sorry, you
should not add pumpkin to the boil or the fermenter- there are starches in pumpkin which the yeast won't (can't) eat. You're just feeding any bacteria that may reside in the wort. And pretty much all beer has bacteria, they're just way outnumbered by the yeast. But when you give them food they don't have to compete for- disaster!
Pumpkin should be left to partial mashes or all-grain. Besides, the real magic of pumpkin beers is always the spices, not the pumpkin. Many commercial examples don't use any pumpkin at all.
Paul, I see you've already done it. Don't worry- I've done it before, too. Drink those bottles fast before they turn. Don't put a 6 pack away for next year or you'll most likely get a nasty surprise.