A few years is an exaggeration at best, unless you're a particularly slow learner. I'd place you easily capable of the mid casual category. Maybe I'm just lucky, but you seem fine to traverse the casual section. If you can write more, it may be a simple matter of waiting for a GM to come along that handles all levels of OOC capabilities. Dumbing down? Kinda sounds dumb.

The main thing is to not show your worse side on the internet. The veterans here are rather serious, perhaps too serious, and don't take bullshit. I'm not that much different, but I do accommodate, and I'd consider myself decent at doing so. Others aren't so much. Remember that it isn't just your IC abilities that people take into account at higher levels, it's your congeniality and ability to interact OOC as well. Anytime you have issues, kill something in the real world (there's a reason why I go cheap on most things). You can blow Terminal out of the water and still be told to bugger off just because you had the maturity along the lines of of heavy spam forum banter for 20 minutes. I'm not nearly as nice as I look, I just take the less nice somewhere else.

Bottom line, establish yourself in the casual category, prove what you can do, keep the stuff that could hurt relations off the guild, and work up from there. Site seniors aren't Nazis*.