Useful tool. Some advice: It seems the order of user is random, I hope there're some better algorithms to present the potential users I may want to kill. The activities of user, times of one user have been killed may count.
1) I would actually love to know what you think would be a good metric for 'do I know them personally'. I believe this would be a big deal for us. We attempted to sort of do this in an earlier iteration by getting your latest @mentions and counting how many times the user @mentioned you and what the mentions were. However the problem was either an extra API call per a person to get the last 200 (the limit by Twitter) or make 1 call and only look through 50. We decided either way wouldn't be worth it.
2) We actually do show if they follow you back, but I guess we need to make it more clear.
3) We also have a recent tweets/day as well as recent tweets. Again I guess we need to figure out how to emphasize this better.
4) This is actually good, how would you go about doing this?
5) Very smart idea, we will start tracking this in our DB. I think.
Thanks for the advice! Right now we're just grabbing the data from Twitter and presenting it without sorting it by any kind of algorithm, but we'll definitely think about how to present the people you're most likely to "kill" first, that's a good suggestion.