[@Oliver] 
Okay, first off, let me start by giving you a belated welcome to the Guild.

Second off, ignore these people. I was told the same thing, even though I am a few years older than you. Just because you are not the same age as some people doesn't mean that you can't write just as well -perhaps even better- that these people that are telling you to dumb yourself down. Just like in the real world, you shouldn't change yourself for anyone, under ANY circumstances. 

You say yourself that you have experience and can usually write around five paragraphs. Hell, that's more than me. I usually average three-ish. The point IS, if you ask people for advice and they tell you to dumb yourself down, then you should't be taking advice from these people. I understand that the community of RPG is generally just a great place to be, as it is filled with some really cool people, but if they are telling you to stick to the free section strictly because of your age alone, it's ridiculous in my opinion. 

The point is, don't dumb yourself down. Do some casual RP's, be yourself, do your own thing.