Hmmm my blacklist never gets near 200 but then I am generally deleting previous days blacklisted people the next day. Since more often than not most get removed within hours some even minutes of the tell(if I'm not next to my system and I get like 3-4 tells from the same person when I try to blacklist it will more often than not tell me that that player does not exist)..

But yeah I agree there should be a report for > reason sub menu on the context menu which opens up a prefilled form about it with you just needing to put in a reason(hell this could be drop down premade with an option of other for those special cases).