Okay, please make sure both Kark and MattyG look over it before you get too attached. I can't look myself, but I am rather wary about role madness games at this stage. That's not a no, but I'll feel more comfortable if I know both of them are okay with it.
I think it is balanced relatively well. Probably could use some more tweaking, but he's on the right track. I think it would be fine for newbies too.
I think in the case of late game, I'd rather let the game go on as normal rather than seeking a replacement. I know it isn't ideal, but subbing in at the last second of a game is also a bad move because that person has to catch up and figure things out and it's a disadvantage in another way.I disagree, especially later in the game when subtracting a player entirely makes an enormous difference. Imagine how annoyed you'd have been if say, RNH had gone inactive on the penultimate AC day. The entirety of town would then have lost for a reason completely outside of their control and it would have made much of the game simply pointless. Yes, there are difficulties reading replacement players, but there are also benefits - if you found both preplacement and replacement suspicious, then that's extra evidence against them, for example.
Also, this is, at the end of the day, just an internet game. At the point people are willing to flake out without telling anybody, they (presumably) don't really care if their team wins or not, so mod-killing that role does nothing incentive-wise.
I would hope that no one would be as daft as to leave so late in the game though, barring an emergency, and at that point I think we all would appreciate an alert so the mod could append time onto the phase appropriately.