Bots win if the mods die. How would you know if someone is a mod? You don't, especially in a straightforward version of Mafia like this one where there are no power roles. All you can do is to try and maximize discussion by either starting one or participating in one. Through all this participation you decide for yourself who you think is likely lying about being a bot, make your case, and vote. This is why inactivity is seen as suspicious since the less the bot knows, the better for the mods.
Whatever suggestion you have might as well tell us now.