Help with my Pumpkin Beef stew please!

I just wouldn't get carried away.  This can be an amazing dish if we take a less is more approach.  Prepare your beef and pumpkin puree separately, and plate them together.  Those spices will work, but remember that you're used to tasting most of those with sweet applications and you're making a savory one.  I tend to season my pumpkin with salt, pepper, and a little nutmeg.  pumpkin puree on top of starch doesn't sound necessary.  

A lot of the flavors you listed sound kind of like a curry recipe, in which case I would use sweet potatoes instead.  So maybe, if you really want to use all those flavors listed you could braise the beef in stock and wine, make a sweet potato puree with your chilis, that cilantro and coconut milk, and then serve it inside of a roast pumpkin?

and a good piece of chuck or brisket will do just fine for this.

I think I'd be more interested in chunks of pumpkin rather than a puree. Roast them off separately from the stew, add in at the last minute to preserve their shape and (minimal) texture.

I'd be tempted to use the roasted seeds in the stew. Roasted and whole as  texture accent garnish or perhaps ground as in Mexican pipian (though not necessarily that seasoning).

If you're set on a pumpkin puree, I'd lean towards using the puree like you would a tomato sauce. So make a Braciole with a pumpkin sauce instead of tomatoes. Keep the seasonings largely the same or take them a touch sweet if want to with a little cinnamon or nutmeg or such.

you're trying to make two different styles of stew/soup in the same pot. if you want to use sage then don't combine with coconut milk, peppers,cilantro,etc. but make something a little more rustic. sear some stewing beef(because you're using beef stock having a bone doesn't matter),add raw cubed pumpkin and onion and slowly saute for a few minutes and then deglaze( this stew doesn't need acid so beer will work as well or better than wine), add stock and simmer for about an hour and then add everything else and finish it off. i don't find stew that tastes like dessert that good so i'd leave out the pumpkin pie spices except for fresh ginger and the smallest amount of cinnamon. for the thai version use a more tender cut of meat and smaller sized vegetables and cook it quicker. if you want to use your chipotle peppers then make a central american or mexican style braised stew and then you can use chilies. broccoli won't work in any of these versions. if you are making a stew then roasting the pumpkin ahead  of time is a wasted step. pumpkin seeds as garnish will work for any of these dishes. rice noodles will be what you want for the thai stew as long as it isn't too thick or a side of rice.