I've dealt with mainly the smaller guys, and I don't believe that clipping is necessary in order to gain a bird's trust. Even if I had a large parrot that flew to bite people, I still wouldn't clip! If you are worried about that, then work on training with the bird *IN* the cage! Start on target training and station training through the cage bars.
I know a lot of people will say that just because I don't have a large parrot, it's different, but that's not true at all.
Here's some old videos.... first set, 5 adult budgies. Three were second hand, plus, birds from other homes that were originally purchased at a pet store and never tamed. They were basically just ornaments. Two came from a breeder as adults. Again, not tame/friendly. I started feeding them by hand every day. If one budgie was brave enough, then the others eventually followed suit.
[ame="https://www.youtube.com/watch?v=fUx81WHTUwk"]1 Bird in hand Leads to Many - YouTube[/ame]
[ame="https://www.youtube.com/watch?v=AlSm4uFZzVU"]More Budgies!!!! - YouTube[/ame]
Now, I only had plans on working with budgies, but I had a hand raised, then neglected cockatiel that had other plans. Took me two weeks to figure out that she wanted the same interaction! (no before)
[ame="https://www.youtube.com/watch?v=q88bN30qOjo"]Sunshine in the Morning - YouTube[/ame]
And then came Faye... at least 3 homes prior to my own and she had lost her mate in her previous one. I'm not sure if her 3 previous homes really even cared about her. (honestly, not happy with the last home... she was the 3rd animal I had taken in from that family...) Faye watched me interacting with Sunshine and wanted the same behavior from the start. You can see how nervous she is in the first video.
[ame="https://www.youtube.com/watch?v=R9w9w8nMRmw"]Hesitant Faye - YouTube[/ame]
Compared to second video.... her behavior is completely different! And I'm also feeding her pellets, not seeds! (she, oddly, took to eating pellets as if she had always eaten them... but I'm sure that the last two homes at least only fed her seeds...)
[ame="https://www.youtube.com/watch?v=rH9ZWxhCSAE"]Not So Hesitant Faye - YouTube[/ame]
Which lead to doing the same behavior with the other cockatiels.... including an ex-breeder (Sunshine's father! Pistachio) that was *extremely* skittish. I never clipped any of their wings to get this behavior, either!
[ame="https://www.youtube.com/watch?v=XjKmHswgiHs"]Cockatiel Feeding - April 24th - YouTube[/ame]
And if you don't think you can work with an aggressive bird while caged.... I'd recommend reading the snippet from this page about working with Fergus (about halfway down - Fergus, a sulphur crested 'too, sittong on the door of his cage chewing on a stick)
https://zoologica.wordpress.com/2008/12/21/living-with-a-cockatoo/
As far as bites go, learn to read body language. Things like eye pinning, beak open, wide stance, feathers slick, wings just slightly spread away from body, neck/head feathers might be opened up a bit. Signs can vary somewhat from bird to bird.