Which one is better, this or Dona Isabel?

Inca ski Amarillo is very good, and sorry I have not tried Dona Isabel

I just ordered this and when it arrived it’s sealed but out of date and a more orange color than yellow. Is that normal?

if it is well sealed and expiration date correct, I see no problem between brands varies from yellow to orange

In Bolivia, we have a dish called, Fricase and we usually use aji amarillo en polvo, does anyone know if i can use this aji amarillo to make fricase?

Well Aji Amirillo is the type of pepper used to make the paste, it is used in pollo a la brasa in Peru. If a dish calls for aji amarillo then this is the pepper to use.

How much of this paste would I use to sub for an aji amarillo pepper?

I have no experience with the peppers, but I would say this paste is potent. I use about half a teaspoon for a 6 serving batch of (my version of) arroz con pollo. You might have to experiment to find what works for you.