Weco, I worked with my birds (the untame ones) in the morning, and only in the morning. I had absolutely no bond with the budgies, none with Sunshine, Faye or Pistachio - the birds I had pointed out in the videos above. All birds adults in these videos as well, in other words, they were all 2+ years in age. Pistachio is, at minimum, 16+ years old and I've only had him for 6 years and a few months. For all I know, he could be in his twenties now! And as far as I'm aware, none of his previous owners ever handled him or worked with him in being a pet bird. In his previous home, he was a 'part time' breeder, and his owner would hand raise his chicks and sell them. Except for Sunshine, which he had kept. I had had no bond with Sunshine, but she was previously a pet. As far as I'm aware, Faye was not a pet in the previous three homes that she had lived in. Her age is unknown, and she had been passed around by people who lost interest in keeping her. She was a caged bird. Tomi Girl was nearly starved to death in her previous home, and I have no clue what her life was like prior to that, since she was found outside.
Akraya, to answer your question... well, I don't clip my birds and haven't for years now... but my mitred conure I have to use a dremel on his beak to keep it in shape. Dremeling a beak is much more intensive and potentially damaging than trimming flight feathers. He hates the dremel, and he knows what it is, but he never holds a grudge against me. In fact, he's usually nicer to me after I have dremeled it!