Okay, first, I think this is interesting, at least on the surface.
Second, I think it's broken as it is right now. Most importantly, you should always be super careful about public effects of the form "Mafia players get X bonus", because it will often be possible to deduce that they are mafia as a result of the bonus. So in this case, the vig effect, all mafia players become BP, well now the vigs can reveal at the start of the day who they targeted and didn't die. It's not sure to catch scum; at least some of the time I think scum can argue the claimer is lying, so it's narrowed down to one scum out of two, and other times, maybe that player just chose the BP bonus.
Here's a plan which I think is broken:
Everyone agree to use vig at night and target player X (everyone shoots the same person, sucks to be that person). If that person doesn't die, we all know they are scum and lynch them the next day.
So basically, town gets two lynches (one at day and one at night) for every one mafia NK; with the exception that they have to use two of those lynches (sometimes) to kill mafia. No PR's effectively, but still a good deal for town I think. But it can also be improved upon by dividing everyone up to have two targets:
Divide everyone up into two groups. Group A vig player X and group B vig player Y. Now you effectively have 3 lynches for every NK (again, with the exception that you need day lynches to kill scum).
The only benefit mafia has here is that they can lie if they get several of themselves in the same group, but then they're really putting all their eggs in one basket (maybe they have to though).
You can probably do better, at least early on, with maybe three or more groups, not sure. The idea behind multiple people shooting the same person is to make sure it's hard for scum to lie.
So anyway, I think liopoil's right and you need to come up with a different vig effect. I'm not sure I like the idea of having multiple vig powers each night anyway, since it will likely make games pretty short. Something to think about.
I like the general idea of the set-up, I like games that are more about theory and coming up with plans rather than the social deduction aspect. I would probably even play this as is even though I think it's broken, because it's interesting. I'll think about it more later, I think there are other ways town can take advantage of the set-up. I think it's really easy to catch scum in a lie with this set-up, even if scum plays perfectly, but it's also really hard for scum to play anywhere near perfectly in this set-up, because there's so much they have to think about, both from their own perspective and from town's perspective, and if town pressures them to post results/claims quickly I'm not sure they'll have time to come up with claims that are consistent with town claims.