A single or even just two geese will imprint on you enough that they probably will not get aggressive and see you as their parent their whole lives. If you have a larger flock who imprint more on each other, yet you have lots of contact with them, that's when trouble can start (at least in my case).
Semi-familiarity is where you can get a goose who does not fear you, yet considers you an intruder. In my experience, these are the kinds of geese who try to bite and flog you. I'll never forget Pinhead, one of five goslings I got at one time. He was meaner to me than a snake, and he was the lead gander.
Funny thing was, he would still eat out of my hand. He would alternately bite my hand and then eat a few bites, then BITE my hand real hard to make sure I knew who was boss.
I have three hand raised geese who are never aggressive with me, including the gander. But the gander is aggressive with my daughters and grandson, because he's familiar with them BUT not imprinted, so they are intruders.
The only way they can be anywhere near him is to scare him away.
Then, you have individual personalities in geese, and some are just going to be aggressive and mean no matter what, if not to you then to someone else, it is just their nature. They don't have teeth or claws and can't fly, so all they have left is obnoxiousness.
I couldn't NOT hand feed any of my animals, and so far, with the exception of Pinhead, I've been fortunate to not have bitey or aggressive geese.