There is nothing wrong with a friendly baby. My DD has always been friendly. Once on a flight this woman came up to me and told me she was "socially gifted, really I know, I'm a professional." Okay, lady whatever. But people have always asked me, "is she always this happy?!" I think it is something to say, and they probably appreciate a responsive baby instead of a grumpy, crying one. Don't worry.
She is still friendly at 3.5 but she isn't going up to people she doesn't know and walking away or anything. If you are concerned that she will be unnaturally friendly as she gets bigger, don't be, there's no reason to think that. She may get shy, or she may stay friendly but you will teach her boundaries. A GREAT book about kids, strangers and all that is "Protecting the Gift" by Gavin de Becker. All parents should read it, really helpful.
I am just so thankful that my DD isn't the painfully shy child I was. You really don't have control over what personality she will have, certainly if she has issues you can try to help her with them, but it would be a mistake to try to make her someone she is not. So yes, let her be Miss Personality if that is who she is.
As for passing her around, if she is comfortable, there is no reason to not let people you know hold her. If she is not happy, well then keep her to yourself, there is no need to force these things. If he's passing her around to strangers, obviously that is weird. And if she gets to a point of not being comfy with others, then you should respect that. They have normal phases of that. Sounds like you might be over-thinking things.