Conures are not one specific breed of bird. Conures is used to describe either large parakeets or small parrots. There are over forty different species that are described as conures. Conure is not a scientific name, therefore it does not have a specific definition.
Yes the green cinnamon can breed with the green cheeked conures.
Probably Jenday Conures, I advise research though
Does the male in any specie lay eggs? I don't think so!
No. Any bird that lays eggs is female.
There is a huge difference in size. Sun conures and Green Cheek Conures are both small parrots, only slightly bigger than parakeets. An Amazon is a medium sized bird and will most likely kill the smaller Conures.
No, not quite sun conures are a little larger than green cheek conures.
Pineapple conures and crimson-bellied conures belong to different species within the conure family, and typically, different species do not breed successfully. While they may display mating behaviors, viable offspring are unlikely due to genetic differences. Hybridization is more common among closely related species, so these two are not likely to produce fertile hybrids. Always consider the health and well-being of the birds when thinking about breeding.
There are a few causes for this. This bird may have a genetic disorder in which feathers do not grow. OR this bird could be a plucker. This means the bird plucks it's feathers. Either way, you are going to want to take it to an AVAIN vet to get it checked out.
no
Some Conures when you buy them do come in pairs but others they come individually.
A mother bird will lay an egg when it has breed with a male bird.
Mine personally love a happy hut over a bird tent if they are the type I'm thinking you are writing about. I think they prefer a happy hut because they actually lean forward and somewhat lay down as a double stacker (there's two), rather than stand up on a stick. The same goes for my cinnamon green-cheeck conure, except my parakeets want nothing to do with a lot of things such as toys, housing, bird baths, etc. It varies from bird to bird, but my sun conures love their happy hut.