I like the division into three separate aspects, though I will admit I wasn't very familiar with the earlier system. I agree with MMC that grinding/vAI Deckbuilding might merit its own section, as the bore of grinding is something all newbies encounter. I don't think there are any other aspects of the games or forums that really require mentoring.
Perhaps we could have some sort of 'Ask the mentors' thread? I know it's similar to the 'Ask a simple question' thread, but we should have something which exposes the newbies to more than one mentor and allows more free flow of info.
Criteria for different sorts of mentors is a bit vague, at least on first reading. How well do you have to place in PvP? How active must you be in CIA? What level of knowledge would be knowing like the back of your hand? I've been TrO for a long time and have a lot of enthusiasm for the event, but even I wouldn't be able to give something like a history lesson on early trials. Does that mean I can't be considered an expert for the Trials section?
Instead of achieving one first place or three top 3s, maybe we could adopt a system similar to PvP WC? i.e. Assign points to placing high in an event, and a person would require a certain amount of points in total to qualify?
As for the strictness of requirements, I believe they should be harsh enough to ensure all the mentors are very good. I'm unsure about what this would mean for CIA mentor, but I agree with 1 year and 200 posts for Forum Expert. They should be required to have a general knowledge of all the public forums though, including rules like which deck goes into which deck forums, the restrictions for joining any pvp event etc. (Or at least they should know where to look for the answers).
So in conclusion, please update the criteria into a proper set of restrictions for applying mentors. The current style is good if you wanted to tell them what sort of experience they might need, but if you want to have fixed rules for selecting mentors they should be clear and well-formed. Also, could the requirements be edited into the first post?