To understand the Food.com recipe you referenced, I compared it to the Libby's recipe which sets the benchmark for pumpkin pies.
Food.com Libby's
Raw measurements
Pumpkin 6 c 2 c
Sugar 2 c 0.75 c
Eggs 8 2
Dairy 4.5 c 1.5 c
Pseudo-bakers percentages (eggs as ratio of cups pumpkin to eggs)
Pumpkin 100% 100%
Sugar 33% 38%
Eggs 1 : 1.33 1 : 1
Dairy 75% 75%
As you can see, other than creating a huge volume of filling per shell, the Food.com recipe you used is quite similar. The main difference is that it adds a lot more egg, so should set up more firmly.
It does seem to produce far, far too much filling for the number of shells specified, even if they are deep-dish.
I would suggest baking the extra filling in ramekins or baking dishes as pumpkin custard for any surplus after you have filled your shells.
Don't add more ingredients to the filling, though; they are approximately balanced already. Remember, pumpkin pie is a custard, and the filling will be quite liquid before it is baked.
I'm going to assume that the primary question is "How can I make a flaky pie crust without wheat flour?" Note that recipe requests are off-topic on this site, but substitution questions are on-topic.
The key thing which wheat flour gives you is gluten. Quinoa is gluten-free, so it's not going to help you much. However, there are ways of making gluten-free breads, cakes, etc. The first hit which Google gives me uses cornstarch, xanthan gum, and gluten-free flours. The second uses arrowroot starch, xanthan, and gluten-free flours. Xanthan isn't the only way of substituting for gluten, but it seems promising.
Best Answer
Yes, since the blueberries were already frozen, you are unlikely to have them making the crust soggy. It should work out well.
You will want to bake it from frozen, probably, rather than thawing. You might want to slightly lower the oven temperature since it will need a little longer, and you don't want the crust to over brown.