Havent been here long, but here is my two cents about how you might improve RP, without strict White List. What I suggest would allow as many to enter (after passing the current quiz/barriers to entry), but also force them to prove they are in the server for the right reasons.
I suggest simply limiting what they are allowed to do as a "NEW PLAYER". I think it is a little silly that new players cant be robbed, but they can use horrible RP and rob others. And get into groups of 2-4 new players, grab a bobby-pin, or just pay real money for a car, then wildly fly around robbing people. This in my opinion is what kills the server.
Force them to RP until they get past new player status. No robberies, maybe even no guns, no bought cars until they get 5k XP, if they want to be a criminal, fine, but they have to find an established gang or crew, roll along, provide a look out etc., but can't directly rob people until they prove they can RP properly.
Understandably, some will just grind their way to 5k, then start acting like fools. But, I think those who come into the server and immediately want to play GTA ONLINE with 300 players won't stick around, and won't want to put in the effort to get 5k XP (which is not a lot really).
The ones who do stick with it have essentially passed the whitelist test the best way you can, by actually RPing to earn your way in.
PS....I wrote all of this because I am so fed up with trying to play a simple ATM Money transporter civilian, and constantly getting robbed by new players with absolute garbage RP, and nothing I can do about it, except report. It ruins my experience completely. I enjoy playing the civilian, I enjoy being robbed and RPing it with good criminal RPrs, but the server rules/setup make it almost impossible to put up with the BS. I was literally seconds from quitting, until the one good RPr I met (Charlie Nightingale) took 45 minutes of time with me to talk me out of it.
If it wasn't for him, Eclipse would have lost one of the few civilians trying hard to RP properly (and doesn't care at all about $$$ and leaderboards) that it has.
PSS.....I should also add, I have an MBA, so for the business side of things, everyone knows the quality of the product = more profits. Keeping quality RPrs, who are dedicated to the server, is a better way to make money. People like me are willing to buy VIP, just because we get it, and want to support the people trying to make this work. I don't particularly care about the perks, and would never buy a car with real money, but I would absolutely pay for VIP just to help fund servers etc. Treat your customers well, they will treat you well back, and for a longer duration.