I can see where you are coming from with the thread. I think right now you are right the threads done whats needed. I also think at this time it would be a bit pre-emtive to lock it right now because no Jagex message has been relayed to the Community about the threads removal.
You are reporting a bug only you seem to have thus you sending in a Bug report is the best and only option.
Thread can't be unlocked as it's a bug you have that Jagex need to address as with all bugs people send in.
Bug reports don't belong within the Forums. They need sending to Jagex in game only.
Request to unlock thread not granted.
The other thread you pointed out is from over 12 months back and it was to do with a recent game update and not a bug issue. Hence no lock on that thread.
Comprehensive Account Security
I've hid the thread and sent them name for review. I know it was reported before and the name was sent up but I'll send it again to make 100% sure it's dealt with.
Also yes a bad name and not something that needs to be left in view for all.