Some commentary:
Empower - each night you may target a player and any night actions they would take now become an empowered version of that power. Examples of empowered actions are;
Problem is, there is no general way of telling which power becomes which. Gets even more difficult to say if the roles he targets are already modified roles. I think this might work in open setups, in closed setups it's pretty random because you have no idea what it does. A "fixed" way of implementing this would be something in the style of Godfatherer, only for other passive abilities.
Shield generator - each night you may place a shield on a player which returns any actions that would target them to the player who originally used he action
So it's basically a Nexus-izer. I doubt that you would want to use this as town - yes it can reflect the kill to mafia, but it can also totally mess up town results.
Mail carrier - 3 times during the day you may send the mod a message to be sent to another player(hiding your identity but being sent from confirmed town or may send a message directly to another player but no confirmation of alignment, or hidden sender an alignment)
This role already exists as "Mailman". I had it in RMM11 and thought it was fun, but it's not very strong.
Live/death roles - obviously we have roles regulated by day/night and even/odd, but I love the idea of regulating roles by alive/dead for example;
Doctor: each night you will target a player to "medicate" upon death, all players who have been medicated will be protected for 2 night(upped to 2 to account for the potential that your targets die before you) the intent being instead of a chance to protect each night, you have no protection while alive but tons of protection after you die.
Cop: while alive you will receive no results of your coppings, upon death all of your results will be revealed to the town
The doctor thing might work out fine, though protection for two nights seems too much (if they live till say, N3, they can turn 3 players 2-shot BP, potentially leaving the mafia with no possible target). The Cop I'm less sure about, I think the whole fun of a Cop role is deciding when to claim your results. If results just get revealed anyway, all that subtlety goes away.
Coward - upon death the mod will randomly chose another town player to take your place.
Well, this is mostly negative utility for town because every time the coward (who is a VT otherwise) would die, there's a potential for a town PR to die instead.
Hero - upon lynch of any player you may(or compulsive) chose to take that players place, their alignment will not be revealed. Potentially compulsive D2 or D3 Hero
Making it compulsive might mess up LyLo situations, but I guess is fine in the first few days. If it's non-compulsive, I think it will hardly ever be used. The benefit is just too small. Maybe have the alignment of the saved played revealed anyway? That would make it stronger.