Have some confidence there! Why does everyone come on this forum claiming to be a n00b every time they make their first post? Trying to draw welcome-beam fire? Seriously, HLP is not a noob-eating forum, there are places on the internet like that, but people are surprisingly mature here (as long as politics, relgion, or the GTC Aeolus is not involved).
Sure, it's not going to get published without some editing work, but it's a great idea. Better than most other people. The fact that you were willing to post your writing is a big step. There are plenty of campaigns looking for storyline writers. Creativity and good grammar is all you need, and you have plenty of both. Who gives a **** about prose?
I'm working on a campaign now, if you're available later I'd like you to do some writing. However, the best thing to do with your manuscript (if you want people to stop *****ing about it) would be to make some sort of campaign of it. As much as people praise FS campaigns for creativity and depth, they're speaking in relative terms. I've seen few campaigns with a creative or deep story, and with your skills, you could do well at that.