#2 sounds like authoressnebula's (https://www.fanfiction.net/u/1523635/authoressnebula) Giving Up Is Hard To Do (https://www.fanfiction.net/s/5405086/1/Giving-Up-Is-Hard-To-Do).

2) authoressnebula's fic came to mind as was suggested, but could also be Practical Application (http://ratherastory.livejournal.com/6995.html) by ratherastory?

3) So Many of Them (https://archiveofourown.org/works/80980) -- velvetine01
In Jericho, Mississippi the gas station clerk says, "He always look at you like that?" as she takes the crumpled bills from Dean. Her eyes follow Sam back to the Impala.

Run Away With Me (Or I'll Keep Singing) (http://fantamae.livejournal.com/4540.html) -- fantamae
"Dude, there's a guy outside, and I think he's serenading you." Stanford era.

ain't no one here but me (http://candle-beck.livejournal.com/120887.html) -- candle-beck
The first thing you should know: Dean annoys the living hell out of Sam.

Two Queens (http://belyste.livejournal.com/7224.html) -- belyste
Dean tries to figure out why so many people think he and Sam are a couple.

Untitled (http://redemptionday.livejournal.com/38496.html) -- redemptionday
It was beautiful. Dean had had Christmases with Sammy before, when they were kids and a couple of times since then. None of it was anything like this. This...was amazing. Sam must have spent weeks planning this.

And since you mentioned weecest, this isn't quite slash, but it's pretty adorable:

Sweethearts (http://spnkink-meme.livejournal.com/2819.html?thread=1772035#t1772035)
9-year-old!Dean and 5-year-old!Sammy hold hands and kiss each other like it's the most natural thing in the world. They also prefer to sleep in the same bed. John is confused and don't know how to deal with it.

1) Can it be Fangs and Fury (https://www.fanfiction.net/s/9366261/1/Fangs-and-Fury) by morgana07? It's post-Purgatory though.

Summary: After another fight, Sam goes out to cool off when Dean gets jumped by vampires looking to use him as bait or food. It's up to Sam to find his brother before he's turned or killed & he's forced to call upon the last person he ever wanted to ask for help or risk losing Dean again. *Hurt/limp/angry/sick!Dean; Protective/concerned/worried/furious/limp!Sam (Benny's here as well)

http://caranfindel.livejournal.com/70724.html
thats the link, is it this one ?

Anonymous beat me to it, but #1 sounds like it could be one of mine.

Here's a little ghost for the offering (http://caranfindel.livejournal.com/70724.html)