Well turning the email password option will only result in a few things:
1. Your users can register any name at any time with any email; this results in a few sets of members:
1a. Members who reg every "likeness" of their name because they want to remain "unique" (i've seen it happen, had one user with about 30 accounts).
1b. Members will reg every "likeness" of other members in attempts to "bash" them.
2. If you ban someone's account it'll take 2 seconds to re-signup; as you have no email password routine they can just simply fill out the form and get access; be prepaired for:
2a. Name Bashing: where user register "[profanity]-[namewhobannedthem]" such as "F*** You Charlie Brown" for example.
2b. See 1a and 1b
