Might as well chip in considering everyone else has
To DB10: You might wanna think about stepping down as a mod, mate, as you do seem to be getting some aggro by being a mod and by your own accounts the workload is heavy. Also, it might mean that you would contribute a lot more to the forum, which is always a good thing. So perhaps the best thing here is to just stop being a mod and go back to being a regular contributor, getting the trouble off your back, and pleasing a few others?
Regarding the locking of threads, i must admit that when you see a topic reach say 10 pages or so that was, for arguments sake, originally a Cesc transfer thread that has decended into a debate about us not having enough defenders, then it would seem that the best thing to do would be to start a new thread, as bigger threads by nature tend to go off topic, and can be a bit infuriating for someone who wished to post on the orignial topic.
So, in my opinion, the creation of new threads on topics that may have been covered before isn't necessarily always a bad thing. However, this is subject to exceptions though, as having 10 different threads on our new kit is a bit over the top.
Ultimately, it is a balance that is hard to reach and i believe that there isn't one set rule to go by, most of it will have to be done on a subjective level rather than an objective one, and take the decision on the merits of each thread at a time.