Nutro Max is very good food, but how you serve it matters more than the food itself. As I said, the daily amount should broken down into two or even three small servings.
Higher quality food, like Nutro, need not be fed in such large amounts as the cheaper brands and is much more digestible. This is an advantage for all breeds and not just poodles.
Bloat is a risk for this breed, as it is for many other breeds, but I would not let it stop me from adopting another dog.
I'm sure nothing you did caused your dog's death and I have never heard of it being necessary to soak poodles' food before feeding. Sometimes these things happen no matter what precautions we may take.