To be honest, after reading that my first thought was that ATPG must be SK. This is in 100% 'SK-ish' offer for a town: let me live, I will kill people for you.
If ATPG is pro-town vigilante, then maybe the best thing he can do is to be lynched.
Why?
Because, now we have a player who CLAIMS that can attack at night and that he is on town side.
When ATPG dies, his role would not be wasted. As I understand, ability to attack comes from boxing glove(s). So, we could vote them to someone else. That way, we would be CERTAIN about what gloves do, and could work with this knowledge, while not risknig almost nothing.
Wow, this text I wrote... I convinced myself.
Unvote; vote: ATPG, as I think he is SK/neutral, and even if he is not, we lose almost nothing
And, if you are townie, ATPG, you will applaud me. Any other reaction would be even more scummy
Not sure if scum, but definitely sure you put gaping holes in your thought process.
Let's assume, for the sake of argument, you kill the natural vig and rely on the gloves. What has changed:
1) No natural vig, so therefore, must rely on the weak vig attack. You might kill someone every two-three nights or so. But there's another thing about the vigilante powers that shows how weak it is: It's not capable of being used as a vigilante item every night. So a weak attack every 2 nights, utterly meaningless. I'd be surprised if you killed one person with it. What you want to do is use them as a protective item.
2) The person with the boxing gloves becomes the target. Protecting people may be possible but, the person who holds the gloves will change every day, due to mafia attack. Eventually they will gain possession of the gloves.
How is that different from now? Instead of a protect on a vigilante, which is an obvious winner, which cannot fail without the bearer of the gloves being exposed as scum, you have a protection on.... who? Who has been essentially cleared of being mafia besides me?
I have ideas, that I will be sharing with someone I trust, to be revealed upon my death (if such thing happens). So we are NOT S.O.L. completely. But it's like saying you don't automatically lose a chess game if you lose a rook. That's very true, but you don't give up a rook without compensation.
So, your plan is pretty bad on the face of it. Now let's discuss your SK theory.
______________________________
1) Askthepizzaguy the Serial Killer wins the game via pledging to kill only the second place lynch candidate every day.
This is poor, because the SK should be free to target whoever they want.
2) Askthepizzaguy the Serial Killer claims vigilante, when everyone knows the serial killer always claims vigilante.
This is poor, because the cover is blown.
3) Askthepizzaguy the Serial Killer begins foreshadowing who he's going to kill, before he has doctor protection. He also foreshadows an uber plan of ultimate awesomeness, which could make him a target before he actually *earns* the doctor protection.
This is poor, because a dead SK is a SK who lost the game.
4) Askthepizzaguy the Serial Killer claims vigilante, making him open to detective scans. One detective scan comes back guilty, Askthepizzaguy will be serial killing no more.
So, without godfather powers/nightkill surviving powers, Askthepizzaguy the Serial Killer basically loses immediately with this strategy.
As a person who has been around the block many times, I am aware of the tactical situation. Askthepizzaguy as SK loses the game with a claim vig strategy.
Now, what prompts this sudden spinal growth from the otherwise quiet and demure Jarrema? Particularly when the odds suggest giving me another shot at killing scum, it's still early. My guess is that Jarrema's team has too much to lose to allow a second lynch to take place, and thus, must aggressively pursue a lynch against me today.
Now Jarrema, allow me to paraphrase a guy named Jarrema:
If Jarrema is pro-town, then maybe the best thing he can do is to be lynched. Why? Because, now we have a player who CLAIMS that ATPG is the SK, and that he is on town side. When Jarrema dies, his role would be ascertained as townie or mafia. As I understand, ability to Bull-Smurf people comes from his unknown alignment. So, we could vote him to death. That way, we would be CERTAIN about Jarrema's motives, and could work with this knowledge, while not risking almost nothing.
Best of all, let's suppose Jarrema were mafia. That's two down, rapid fire. And the closer the mafia are to being defeated, the closer we are to winning the game. And if Jarrema weren't talking out of his butt, and he were a serial killer, Askthepizzaguy would get lynched the instant the mafia were defeated and the game continued.
Now then. let's finish off the mafia and see if the game continues, why don't we?
I, for one, am in so much suspense. I don't want to ruin it for the rest of you, but if you haven't figured it out already, what I've just stated guarantees a loss for myself if I am a SK, but pretty much guarantees a town win if I am a vigilante.
And it don't mean a thing if you ain't got that swing. Swing, Jarrema, swing!
Vote: Jarrema
And if you were townie, Jarrema, you would applaud me for the dead mafia that are about to pile up in Pizzaguy's Corner. And for avoiding the silliest lynch premise I've read since Beefy died in Askvaard's return.
Now I must say that's really convincing. We should try this. Vote: Jarrema, and the boxing glove can go to choxorn. All of the Smurf Berries too, I can't eat more of them. 
