I need help with Alexandrine Parrot that I rescued. My question is big. Please see details.?

He will definetly need better nutrition- since he won't eat seeds, i would try finding ways to supplement (dusting his food with vitamins/putting drops in his water) and always offer seeds, hopefully he'll decide to try them. As for growling, it could just be a general fear of handling or the molting. Birds often become very grumpy during this time, and if hes looking kind of scruffy his molt cant be going too well for him. They can last anywhere from one month to as many as 6, it just depends. Right now I'd focus on his diet and getting him acclimated to you and his new enviroment. Offer him lots of stimulus through toys and try and spend time around him. He doesnt have to be on you/touching you, just you sitting near/talking to him should be enough. With propper care and time he should be okay. (On a side note, he might be bald from stress plucking- he probably wont ever look like the standard, but hopefully he will end up healthy)

Malnutrition could be part of the problem.

A good mix of seed, assorted fruits and vegetables, nuts, will all help.

Handfeeding the favorite treats will help with socialization.