I support this. I get rather annoyed when I browse the different sections, and I see somebody attempting to make a sale that is clearly a scam, or somebody trying to purchase something with the intention of scamming, and it's so obvious, but I can't do anything about it and theres always the people who won't realise, and will end up out of pocket. I believe the idea of making it a requirement to read through rules etc before you can post would not work, as I know when I join a forum, and I see something I am supposed to read, I instantly click that I have read it and move on. I rely on my own maturity and intelligence to realise when a deal is legitamate and when it's not, but unfortunately there are many Sythe users who aren't as intelligent (No I'm not trying to be vain, I'm just pointing out that I do have above average IQ etc, so I am fairly intelligent and that other users may not be).
I would also expect it would be a better idea for current Administrators and Global Moderators to hand pick the users to gain the rank of Market Guru, otherwise Sythe will be flooded with applications from all randoms as they will see it as an easy path to trust. I don't think there is any need for more than 1 rank, I would say that Market Guru rank alone is enough for all the users selected to be in this group. Obviously as you mentioned, they cannot have any form of power, nor a misleading user title, as this position should not gain the user any trust in my opinion.
I do think it is a good idea, as I myself before have complained about the amount of time it takes for a RaS thread to be replied to, and how many scammers I see in the market sections that have not been banned. If this were to be implemented, then many scammers would be banned before they actually carry out a scam, or would recieve a TWC rank before getting a chance to scam, therefore reducing the amount of threads made in RaS, reducing the amount of work for moderators, making Sythe a much safer place to trade, and most of all ensuring the happyness of users as they feel safe and as though people are actually trying to protect them.
I barely make threads on Sythe compared to other users, when I come online, I generally just browse RaS, dispute forum, suggestions and feedback. Just by browsing, I manage to find a huge amount of ban evaders. It is easy to notice somebody who is suspicious, and a huge amount of the time they are ban evading, I don't tend to report this as my reports can take weeks to be replied to, and as soon as the user is banned, they have another account minutes later. Sythe needs people dedicated to reducing scammers, and banning ban evaders instantly, and eventually they will get bored. Also banning those obvious scammers before they achieve their goal. I believe I could help Sythe greatly in it's efforts to reduce scammers, but I would not expect to be even considered for such a project, but I am certain there are more people like me who use Sythe, who are intelligent and can spot a scammer, and also have maintained a good reputation on Sythe over a long period of time and would do a great job.
If this idea was used, 1 last thing I would say to anybody who gained a position in the group would be to put your own possessions on the line to save others losing out. Obviously I don't mean let yourself get scammed in order to get somebody banned, but for example, if you notice somebody suspicious trying to buy Runescape accounts and you have 1, sell them yours, go first in the trade, and see if they scam. Runescape accounts are always recoverable so you will not lose out, but I would greatly respect anybody willing to go to those lengths in order to make Sythe safe.
Enough of me blabbing, theres my opinion.