4. I do not quite understand this question.
I'm surprised you understood the others, because I'm having a hard time figuring out exactly what OP is looking for as far as information goes.
There's no rule against, or a general problem with, members having multiple accounts here. A lot of senior members have alts, and sometimes more than one. So having alt accounts won't get you tagged simply because you have them and somehow they get discovered. What leads people to earn negative trust is using them to simultaneously enroll in signature campaigns or bounties, which is what I think OP alluded to.
Also, if one alt is found to be untrustworthy (by being labeled a scammer or what have you), then generally that person's alt accounts will be tagged as well, assuming they're known. That happened to Quickseller a while back, and I've seen it happen to quite a few other members whose names I can't recall at the moment.
OP, if you can make your questions a little bit clearer, perhaps the community can be of more help.