Free-feeding protein is putting their protein food (seeds, pellets, avicakes, nutriberries, nuts) in a bowl early in the morning and leaving it there all day long. And, PLEASE!, no meat! Parrots, with the exception of one and possibly two species, are all classified as herbivores, they do not consume meat in their natural diets. They might eat a small amount of insects (well, some cockatoos eat more than a small amount) but insect meat has virtually no fat or bad cholesterol and, because they did not evolve to consume any bad cholesterol, nature did not give them a mechanism to get rid of it (as carnivores and omnivores have) so it accumulates in their system and ends up killing them. We have a good member who adopted an amazon with high cholesterol and although he spend thousands of dollars in vets, tests and treatments and worked like a maniac trying to provide her with an excellent diet, medicating and special housing (the bird had fatty tumors in her feet and body), she did no make it. I had birds in my rescue who had been fed meat and their cholesterol was so high that it ended up as deposits in their eyes! My senegals (I have a male and female) and all my parrots eat gloop with raw produce for breakfast and all day picking and a measured portion of a good seed/nut mix for dinner.
As to the light schedule... well, the thing is that all birds are photoperiodic, a long word that means that their endocrine system (the one that controls the physical reactions to the seasons) is governed by the amount of light they receive daily. As the days get shorter or longer with the different seasons, the bird's body reacts to the changes by starting or stopping production of different hormones, the sexual ones being the ones that most concern us because when a bird produces them all year round, year after year, they end up sexually frustrated and in chronic pain. This is because their gonads grow during the breeding season and shrink during the resting one BUT, if you feed it high protein and keep the days at a certain length all year round, you end up with a bird that continues to produce hormones non-stop and whose gonads continue to grow until they are so large, they start displacing other internal organs. And this is when they start screaming, biting, plucking and even self-mutilating. Senegals breed in the fall, after the rains stop, so 12 hours of light is perfect for them to breed. The other thing about photoperiodism is that the whole thing works kind of like if the bird had an internal stop watch to measure the length of the day. This watch gets turned on with the dawn and stops with dusk -this is because it's the different spectrum we get at twilight that actually activates or deactivates the 'clock' so for the solar schedule to work, the bird needs to be exposed to both dawn and dusk so its body can 'count' the number of hours in between the two events and 'mark' which season it is.