The reason I asked about her age is that this is often baby behavior learned from the parents. The head bobbing behavior is their version of adult behavior as is chick clucking.
Resting in your shirt is common female aratinga behavior. You may notice her changed scent that she is rubbing on you to claim you. What I find funny is when a conure chooses a toy or case or some inanimate object.
Again, female Aratingas are fairly quiet accept during hormonal periods when they begin the squeaky noises you speak of. After the chicks hatch, the clucking begins.
Based on that video, she seems to be in the early stages of hormonal behavior. As I said, there is a good chance that her behavior will only be a regular annoyance and stay minimal. Regurgitation may be limited to perches or her beak only.
As I said, since she is a single conure, her hormonal behavior will probably be limited. It's nice to experience only the least but wiser to prepare for the worst. After this has happened you can expect this in the future. Be aware that conures can interbreed!