Firstly i wanna apologiez if my post isn't upto standards on what's required for Role ideas.. All what what im suggesting is based on my own and multiple players opinions and experiences. If my post is in wrong section, again im sorry i haven't been active on forums before.
1st: Medium
Ultra passive role that has very little to do overall. The problem with this role in current form is that, player does have to do anything really( many even afk/leave). I would argue even if average/most players tried their best on this role, all they would be able to contribute for townies are messages from dead and vote with town. Some would counter argue that as messages from dead's are important, but i have very often seen medium post's get ignored or not believed (because this role dosent really have a action/ability to "confirm" them) because evil roles claim this very often aswell thus players like refer getting medium as "medium curse". Players who argue that talking to the dead's is important but more often than not players leave once they are dead and/or they have nothing which isnt in their will already.
What i would suggest?
Add an ability for medium to talk to someone who's alive for 1 night and once per game. Medium has to choose one player during day similarly as jailor chooses who is getting jailed to be able to talk to them. This would give more depth to medium role since its kinda occultist role anyway and makes sure medium's would have reason pay attention to chat and what's been said, so that they make the right choice to whom to talk during night. I cannot see how this would make medium too op or broken, just adds reason for medium's to stay in game and have something to contribute.
Jailor
This will be controversial. Currently if you take randomly 10 games chances are that u get something like 9/10 games jailor revealing themselves during D1 so that players can very easily ( maybe too easily) confirm eachother. For townies this is viewed as a good thing but for any evil its really nightmarish sitsuation trying to claim something or try to do something. Currently i have seen great majority players who get evil roles nk/maf leaving/throw as soon as jailor reveals themselves because it become almost impossible for them try and claim something that would even have a chance. For players who say that there isnt anything wrong with jailor revealing, just think about how are you meant to play evil roles from there on knowing there's always multiple tp's and ti's on jailor most likely whom have confirmed eachother.
What i would suggest?
for this i actually would have few ideas but i think this is the best one yet.
Remove the option for jailor to type in chat/whispers complitely. This would also make jailors pay more attention, so that they cannot rely on others info all the time. This would also even the playing field with town and evil roles since there would not be like 4-7 confirmed by D2 because of revealing, and would actually make townies work for their info and who to trust.
Amnesiac and Survivor
I honestly cannot see why these roles aren't currently in ranked practice or i just have not seen them at all. They add couple more intresting roles and little randomness to the game so that it wouldn't be as straight forwad. I suggest that in game there could be only 1 of these so either or type of thing.
Anyway thanks for anyone who read this. Please note that english is not my first language, so there can be some typos.