And in answer to splitting topics and so on, the answer is YES they can be split and merged etc.
If a locked thread needs to be updated by the writer, can this be done?
Yes. I have done this a few times. A simple request to the Moderator to unlock it followed by a request to re-lock it when the changes are done....R
the only way for topics to appear there is if a moderate MOVES a post from a more specific topic, AFTER it has been discussed, edited, and a final form more-or-less agreed upon.
As far as meeting an implied quality, we should take care.A volunteer puts time and effort into making a tutorial then 'the powers that be' says this doesn't meet our acceptable level.
IMHO if a Thread is started somewhere with the ultimate intention of being a tutorial and if there is discussion about it then it should become clear, without offending anyone, whether it meets with general approval.
IMO, limiting tutorial count can lead to being too artificial and subjective.
As far as the moderators go, they are busy enough to be 'tutorial police'.
Giving someone 1000 things to read is no more useful than giving him nothing.