What about adding some script that will search for "reject*" and "blacklist*" in topic and body when users with less than 10 posts are trying to create a new topic? If the script finds matches it can give them some prominent onscreen warning, with a short text and a link to the appropriate topic for asking about rejected and blacklisted bands, that they have to bypass in order to submit.
I'm no programmer but that sounds like a lot of work for something that is most definitely overkill.
The current situation is obviously causing a lot of extra moderation, and the feedback to the users is often very negative, if they even get some feedback; it seems like topics sometimes just gets locked without explanation. I don't know how motivating this routine is for new users, while all the unnecessary topics creates a lot of mess and pushes down more relevant topics, to what I expect is the annoyance of everyone else. I know users are "supposed" to read the rules, and that they probably say yes to it at some point during the registration, but all sites have this and very few ever does read the rules when they register somewhere; it is counter-productive and evidently not realistic to expect that they do.
Well, let me tell you how rejections work from a user perspective.
The user's band is rejected, he receives the following email:
Sorry *user*, Encyclopaedia Metallum was forced to reject your submission for the band *band*, for the following reason:
If you want to object to this rejection, please do so in the appropriate thread
in the Suggestions and Complaints sub-forum. Do not e-mail moderators directly about this.
- Azmodes, Encyclopaedia Metallum
Note that the thread they should post in is very clearly linked here. Not much room for interpretation. Still, as you observed, some people can't seem to grasp even this simple exercise in reading comprehension, but I doubt the owners are going to create some fancy, spoonfeeding script to accommodate said group.
Those unwanted threads you speak of are (mostly) locked without further ado because we make it a point to not oblige people's inability (or unwillingness?) to follow extremely simple instructions. We link to the correct thread and close it. Seems perfectly alright. Seriously, the system isn't exactly rocket science, you don't even need to read the rules to figure out where to post your objections. It's all in the email.
Also, I don't think the current situation is really that bad. Moderation is manageable in that regard, a few stray threads here and there are easily dealt with.