I write because I am driven to write. I rarely share and have never attempted a query letter for publication.
The whole reason I like the sci fi gendre is because you can cover controversial subjects, remove them one step over and one step forward from the real world and they are less forceful yet carry the point just as strongly. Sci Fi people tend to agree with whatever I'm doing anyway.
My recent work started in Jan 07, which I hope to finish by 12.07, is about genocide and the destruction of human dignity and it came about from research on the Darfar. Only a minority of the work is extremely dark, but what is dark is as bad as it gets. I tried to soften it a great deal but there aren't many ways to soften child rape, neighbor rape, torture etc. I'm pleased with how those particular chapters are playing out in the sci fi context. I kept it short, concentrated on characters threatened with, rather than living through it, and rescue two characters just in time, but the conclusions are there to be taken by those who face up to what they are reading. Blood stains on a young girl's thighs, a main character almost disembowled to force another to an act. Pretty grusome, but when you read the accounts on the UN page on Darfar--what I did was damn tame. I'm pretty sick about our apathy to what's happening there.
Maybe the reason I wrote it this time will get me to actually find someone to put it out there...
Writing for the masses, I can't guide you. Writing for yourself? After almost 35 years of writing---there isn't anything out there more important or that you are more likely to complete than the issues that tear you up inside. Go for it.