Our vet takes off like the top third of the ear! He doesn't do the ear notch, because so often feral cats have tattered ears from fighting - and it can be really difficult to tell the difference between an ear notch and a small rip from a fight. I think our vet lops off too much of the top of the ear - but a nice, straight surgical slice cannot be mistaken for anything else.
Once you get them coming regularly for food, it won't be too difficult to move it closer and closer until it's where you want them to be.
As to pets - that's something I'd hold off on. It can be so hard not to just want to love all over them. But when socializing feral cats, the best thing to do is basically ignore them until they come to you. In this case, with outdoor kitties, avoiding any signs of aggression is really the best thing to do. In fact, you may not have received the advice not to look them directly in the eyes. Look at them on the forehead instead.
But once the kitty rubs on your legs, or headbumps you on the leg or foot, then it's OK to slowly reach down, palm down, and let them sniff your hand and give a tentative pet. If they're not ready, they'll skitter away.
We're caring for two feral boys that skitter when we walk toward them, come up to us when we put the food down - and want love and pets from us before eating. So we always leave, let them eat (we don't live in an apartment), then go outside when they're done for pets. They stick around to clean themselves afterwards. We're now able to brush them. They had Revolution applied, so they don't have fleas, but we're working on getting the ticks off of them. They're so friendly to us now, in fact, that I put my hand on the chest of one of them and put his front feet in my lap - and he crawled up into it! But the rustle of a stiff breeze will make them bolt. And if any other people go by - that's fine. But if they look like they're coming here, they bolt.
So I think your being friendly to them won't result in them hanging out on people's doorsteps. But if THOSE people are feeding them, that's a different story.
What you may do is find that some of them are strays, not ferals.
If you do end up petting them, go real slow with it. As I'm sure you know, cats can get overstimulated. Our indoor guys can now handle almost endless pets and brushes. But, for instance, Tuxedo (all of our indoor kitties are feral rescues) could stand exactly one pet on the cheek at first. Now, when he doesn't want any more pets, he either picks his paw up and puts it on the back of our hand, or he puts his mouth gently on our wrist. At first, he'd just swat at us. So if a kitty indicates he or she wants pets or is ready for them - just try one pet on the cheek at first. Stop - and if they bump you again, pet again. Just go real slow, and definitely pet less than you're sure they can take - you know what I mean? They may not know they're becoming over stimulated, and may not give you the polite message to stop.
Are you still in touch with animal control or a rescue group? If so, if you find you've got strays in your group (which is very, very likely), and they warm up quickly, you might want to find out if there's somewhere they can be fostered, or if any of the shelters give the kitties foster time - because friendly strays deserve to be adopted out, if possible.
You're doing SUCH a wonderful thing! And I'm so glad your first time round went so smoothly.