thirsty1) People don't realize that once/if a comment has been sorted into the suspicioius comments section, deleting it will automatically mark it as spam. (It would be preferable for the "comment deleted" message to say so, but this is easier I think).
2) Journal owner is the only person to see the suspicious comments.
3) I'm not sure if this is from the comm's manual whitelist, general community whitelist, the spam protection, or an unholy combination of the above, but sometimes comments are screened. The FAQ should make it clear that it's from one of those and then links to how to get rid of it/instructions on how to disable the autoscreening, since many sites get blacklisted.
(ah, also, can someone add the tag "faq338"? I can't create tags.)