Lastly, Power roles do need to come back to favoring town, and I mean just giving town power roles that help. Watcher and Tracker have such a super small chance of even doing anything in a game, and if you happen to see someone who isn't scum it can hurt you. IC in reality gives scum just as much as town a voice to follow and doesn't amount to much of anything, Robz use in the last game was amazing with it and still it equated to nothing but robz being forced to call a few lynches(this is worse than town trying to work toward a lynch together because it eliminates scum having to throw their voice in) We need more cops, cop catches scum or creates an IC each night he is alive and hits his target, on day 3 a reveal should create 3 IC's(depending on who is living) that would just about end the game, but hey all 3 people managed to live and cop was never blocked(oh yea roleblockers for scum should be back too, as well as a rolecop) then I think town deserves to have that advantage. I would say cop and JK work great as they can hurt eachother but they can work real well against a roleblocker/rolecop. Or give town a doc/JK/Rolecop and give scum a roleblocker. That way town has some huge saving potential and has a cop sortof, though getting back a vannilla result wouldn't give the rolecop any clue of alignment so it makes it a tad harder to create IC's and catch mafia. This way there are some huge PR's going on which influence the game and some vannilla's watching and trying to guess who is on their side fighting for them, who has knowledge of their alignment, and whose claim do they trust based on what makes sense for that player to do(see the last mean girls game, in retrospect doesn't my claim seem obviously right in the grand scheme of things vs ash's opportunistic play/bussdriver and yuma's radomly changing watcher role that watched the silly targets)
I disagree about the cop aspect. I think cops are by far the absolute worst role to have in a mafia game... and by worst I don't mean that they are weak, but rather that they are absolutely no fun to play with. Why? Because cops take the least amount of skill required to use them. Like you say cops are guaranteed a result: town or not town. That is huge, but more importantly it can completely eliminate a scum team just like that, boom, game over. Good game it was fun, but not that fun. Sure playing cop takes some skill, but not very much.
Whereas other roles--yes watcher is pretty weak--require much more skill in analyzing wifom, interactions, etc... And I think you give tracker a bad rap. It is actually a really good role. Because like cop you are guarnateed information: targeted someone, didn't target someone, but isn't as crushing as a cop investigation... it is especially more useful when mafia teams have other roles (rolecops, etc).
I am actually very intrigued by the roles of non-cop investigators... hence my game that I am hosting (Clue Mafia) having two investigative roles (detective, psychologist) that are powerful, but not as overwhelming as cops.
I think other powerful roles include Masons--I think every game we have played with masons, town has won yes?--JK (in my opinion the best and most powerful role in the game) and Commuter and I would like to see all three in more games to an extent, especially if the choice is one of the three and cop.