I think that all of the ideas presented here are excellent... for scaring off any new potential members, be they idiot noobs or otherwise. I can't really comment on the situation here as I am very new myself, but I can't imagine it's any worse than any other public internet forum. That's what happens when 12 year olds and people with no life and have nothing better to do are allowed to use the internet. If you want to gate off the community, it will surely slowly die as new members will be few and far between, especially if the requirements are strict. Sure, you most likely not get any more idiot noobs, but you will also lose many serious and intelligent potential members in doing so. I know I wouldn't have bothered joining this community if it were some sort of exclusive, elitist group with strict requirements to get in, and I don't consider myself to be an idiot noob although others might disagree.
Like many I didn't own a Neo-Geo growing up as it was too costly, and there were no arcades near where I lived. Now that prices have gone down and I have more money, I am able to buy some Neo-Geo games and enjoy what I have missed out on throughout the years. This is one of the biggest and best communities for getting started with Neo-Geo stuff be it tech questions, buying/selling stuff, or just general discussions about the history/games, reminiscing, sharing experiences, and various other topics. I may not have much experience with the Neo-Geo or knowledge about its hardware, games, and legacy, but am quick and eager to learn. There's really no other place quite as good as this one for everything SNK and Neo-Geo related, so please don't rob me and others like me who have a legitimate interest and desire to contribute of a place this awesome just because it's getting overrun by noobs lately. Noobs will always be on any public internet place and even in some private ones no matter what you do. Although in my experience I have found that if you pay little attention to them, the majority of them eventually go elsewhere to pester people who will actually react to their idiocy. When you are patient, what is left behind from the slew of noobs is a handful of serious dedicated people who might have been put off from joining the community had there been strict requirements and restrictions to becoming a full member.
Really if this problem was to be solved we would have to implement my idea for the internet I've had for years. Make everyone who wants to use the internet take an intelligence test of sorts every year and split the internet into two levels. One where the only ones who are allowed in are the people who can actually type intelligibly (very important requirement) and contribute meaningful things can have discussions and conduct business without fear of having to deal with idiots. Then we have the other level where all of the noobs are stuck and are free to flame each other and compete in idiocy to see who is the supreme tard to rule over the other tards. Noobs cannot transcend into the upper level of the internet unless they have proven themselves to be capable of intelligent conversation, and I'm pretty sure those already in the upper level wouldn't dare to tread in the idiots' territory. Then everyone would be happy, but alas it's not very realistic. One can only dream, right?
Just my 2 albeit very lenghty cents.