If the game is in any way townsided the solution would not for me be adding in scum power, even something weak like a 1x doctor (which I think swings the setup well into scumsided). I do in fact consider the loud fruit vendor to be fairly self-clearing for what it's worth: short of D1 lynch, N1 vig (or I suppose the fruit vendor sending to the player the vig shoots), or N1 gunsmith (all of which are admittedly possible), the role is going to be put in a very strong position from D2 onward.
If the role is outted at any point, I don't see the town realistically vigging, gunsmithing, or lynching it, which gives the mafia plenty of strength so long as they can keep the role from being eliminated prior to the point where it has been done. But there is in fact that very realistic chance of the role being eliminated prior to the point where it can be used effectively.
Basically, I realize both sides have some fairly strong roles. (Gunsmith/Vig both are strong, the loud fruit vendor is situationally strong--which is the best type of role to give a scumteam.) As a result, their early death does induce a certain level of swing. I feel like the level of swing is within acceptable margins though. The town has no protectives; their investigation roles are wide open to attack. If the town roles survive via not being outed and manage to produce results...they should be rewarded for that. If the scum fail to kill the town's PRs and let them generate results...they should be punished for that.
If the town fails to protect their PRs by outing them before results can be given...they should be punished for that. If the scum succeed in killing the town's PRs and deny them results...they should be rewarded for that. If the town manage to lynch the scum's PR, they should be rewarded. If the scum fail to utilize their PR to its potential, they should be punished for that. I won't say the town letting the scum's PR be used to its full potential is punishable, but I will say that if scum do utilize their PR to its full potential, they should be rewarded for that.
The setup, as it currently is, rewards good play from a side and punishes bad play from a side. At the same time, there is a built-in level of countermeasures against an early setback dooming a side--namely: if the scum lose their PR, they can still systematically kill off the town PRs (thanks to the town lacking protectives). If the town loses one of their PRs, they still have two others which are of respectable strength. Optimal play simply ensures that these situations are less likely for a side. While luck of the draw does factor in, this luck is mostly in who draws what roles.