As for the original setup, I don't think it's possible to balance it because it depends too strongly on players outguessing the mod. I had players very upset at me once for putting a Mafia Neighbouriser into a game, as they were under the impression (for whatever reason) that Neighbourisers were automatically confirmed town. If players think that when there's no theory reason to do so, it's very highly likely that they'll think a Neighbour pair won't be all-scum when there
is
a theory reason to do that. (And Mason-pair, Neighbour-pair isn't implausible as a setup with town/town or town/scum neighbours; it's probably slightly townsided but not by so much it wouldn't be approved if that's what the mod wanted.)Or to think about it another way: a sizeable minority of players would likely consider this setup to be bastard (even though it isn't by the site's definition), and that's not the sort of thing players are likely to be looking for in Normals.
I'd recommend you do one of the following:
- Throw out the setup and run an entirely different setup (we have pregenerated setups available, including at Micro size);
- Run this setup modified in a way that balances it, at the cost of missing the point behind the setup (changing a VT to a Town Neighbour and a Mafia Neighbour to a Mafia Rolecop would work, for example);
- Add a couple of mechanics that don't really change how the game works and just serve to obfuscate things (e.g. an ability to screw with deadlines), then run it as a bastard Theme (this is likely to be the only way to make your original idea work as is). You might need to add a bit more town power to balance that, if the setup's going to be balanced against the player's mod-outguessing skills.