I was a new player once. I remember being rather overwhelmed (and underwhelmed) with the game on my very first character. I joined the Barony and loved the color, but there were all these things I didn't understand. I gave reverence to people who had positions, etc. and just tried to figure out what I was supposed to do and what was going to be effective. I actually didn't make a second character until six months, maybe a full year after. (Yes, I know I can go check and prove myself somewhat wrong... but it was a while.) Then, I got him in deep and was scared to make another character after that. How would I maintain one character as a "model citizen" (for Vikings, at least) and the other as a crazy mess?
Now I have four characters. One, admittedly, is essentially quiet and pokes her head up every now and then. Two are loud and defining of my play. The last is that abused advy everyone seems to have. I feel like I get the most reward, as a player, out of the advy. I know my contributions are small, but nobody else can get it done.
My point is this: I don't know that changing the character limit will change anything. I think having the option there (and allowing to choose an advy, if you want) is good because it essentially gives you several chances to try the game out different ways, but I really don't think it's part of the problem at all.
Just my two cents. Sometimes, we can't remember how it was to be new.