Hmm interesying question. Using binary search, determining one letter should require about 4-5 tokens (expected half half). I don't have the game in front of me so not sure how many there are).
Yep, we played for the first time last night and this is exactly the strategy I used right off the bat. It takes about four tokens but you know the first letter which is very useful. We played a bunch of rounds in a row and in the final round the villagers narrowed a Ridiculous clue down to a politician with the initials W.M. with this strategy and shortly after figured out it was Walter Mondale (all without help since the Mayor was the Seer). Very effective.