Hey I might have two fics for you one for #2 the other for #3.
Although they might not fit completely into your request I'll still give you the names and such.
They both are by rei_c, I don't have any direct links right now, but she has a link to her master post on the right side of her journal.
#2 would be Bloodlines: Dean and John are turned into Incubi and they need Sam as their focus. They near rape him the first time, but Sam gets away and learns how to deal with them and how to be their focus.
#3 would be Under the Bridge: It actually ends as John/Sam so if that's not your thing don't read it. Sam has grown up with the demons and they shape him to be their leader. John and Dean come into the town where Sam lives and have no idea who Sam is. So they try to solve the mystery of the boy sitting under the bridge.
I'm not that good with summaries so maybe you should just check out rei_c's journal for more info.

Wow, I know the author, I read the 5 districts and 5 drugs one, though not the bloodlines, I will check it out, seems a pretty good one, thanks!

1) Does Teen Antichrist fit your evil+bottom sam criteria
http://community.livejournal.com/inlowercase/3503.html

Definitely!!!
OO,God,finally got a list of journals that are evil bottom sammy...
Thank so much!!!

And So Awakens Devils (http://concernedlily.livejournal.com/37018.html)

It's been a while since I've last read it, but I remember it being damn good.