Yes, I bet she is 'all over him incessantly' - she is a baby of a highly social species which means they are hard-wired to be surrounded by other members of their own species all the time. She is getting exactly what she wants AND needs from him right now (she will become more independent as she matures) so, personally, as long as he doesn't mind too much, I think it's FABULOUS!
Yes, You-You will adapt very easily to a solar schedule. They all do. It's the way they evolved to live, from sunup to sunset, so going back to what it should be will be no trouble for him. It's not even something they can either decide or choose to follow or not follow, it's their body reacting to the different light of twilight - a completely involuntary reflex. The different spectrum distribution (much less blue and more red light), the lowering of the angle of the light and the waning of the intensity slowly morphing into darkness will make him first hungry and then sleepy (the gradual darkness makes their bodies start to produce melatonin which makes them drowsy). It works the same way for every single diurnal species on Earth so he is not going to be the exception. The trick is to expose them to twilight. Some people think that a bird can go from bright light to darkness by covering their cage but nature doesn't work that way (there is no such a drastic change in nature, its always gradual unless you live in the Artic or Antartic circle where they have twilight for months).
Free-feeding protein means putting a protein food in a bowl in the morning and leaving it there all day long - protein food being seeds, nuts, pellets, avicakes, nutriberries, etc. Protein is not that easy to find in nature for hebivores... There are nuts and seeds, of course, but there isn't a single source of protein that is abundant all year round. Plants bloom and fruit in season, not all year round and even when there is an abundant source, say a large grove of trees that produces nuts, it's not as if there were only a couple of birds eating from it so the entire crop is eaten in a matter of days - same with fruits. We had a VERY old and large fig tree in the backyard of our summer house back home and we always spent the entire month of February (the equivalent, in season terms, to August here in the Northern Hemisphere) there, and we would watch the figs very carefully every day to see if they were ripening because, once they started (the ones at the end of the branches and on top of the tree were the first to ripen), we would hurry up to collect them because, in a matter of two days, the parrots would have eaten all the fruit on it. And that's the way all birds eat. Once they find a source, they eat and eat and eat from it until it's finished and then move on to another source -always of a different type of food. So, to a bird, having protein easily available in large quantities all the time is completely unnatural and unhealthy because birds in captivity can only use a portion of the protein the wild birds need (wild birds fly for miles and are exposed to the elements which requires more calories) and the rest becomes fat which ends up being stored as fatty nodules in their livers (hepatic lipidosis - aka fatty liver disease).
They crash against each other because she is not very good at flying yet. I know that she looks super proficient doing it, zooming around the house, but, in reality, they need months of practice to master the art of maneuvering, landing and stopping on a dime. She will get much better at it and they will not crash. I always have 8 and, sometimes, up to 15 birds flying around and they only crash (and not only against each other but also against me
) for a month or so when the new ones first arrive because, even when when they come flighted and good at it, if they were only birds, they need to learn to avoid other birds in flight. Let them practice and don't worry about them crashing... they will learn, you'll see.