No it's not possible to edit the mods on the workshop because the files are encrypted. Only way to edit them is if the author lets you download the local unencrypted version.

I'm probably one of the few who does that. I would not recommend looking at my files though, there is so many changes you will get an heart attack . You've been warned:
http://www.mediafire*com/folder/fq1barpa58b5h/Mods (replace * by a dot)

You should read the Modding Instructions pdf first to get a basic idea of how the modding tools work. It's located inside the game folder next to Storyteller.exe (modding tool).

I, actually, was going to ask you for sharing your raw mod files, Kierk.)

I edit my mod description so many times I forgot to put it back. The link is still in the FAQ thread of my main mod (Last Stand) though and now also in the modding tools guide I'm working on.

Anyway, whatever you both do, be sure to use WinMerge and compare the whole mod folder to a newly-created(blank) mod to make sense of all of it. It's not that complicated. I always put the newly added entries after the rest. Like with Winter config, you've got all the different timelines and at the end, right after the Fading Embers timeline (WS_Story3), I add mine (either Survival or Endless). It's like this with all the modded files (the ones with a .bin file next to it).

You can also open the whole mod folder with Notepad++ to search for all references to a timeline inside all files at once (Scenarios, Scavenge Locations, Radio, Visits, Winter mostly).

I'm fine with reading xml markup, being a web/UI-designer for 10+ years I have experience with html, css, js, even a bit of php and sql queries.

You should feel right at home then, everything is in xml No obscure language, not even a single script code, just beautiful xml files. It's super easy to read. Can't say the same thing of other games unfortunately (modding in hex is pure nightmare fuel).

Yeah, HEX is quite a riddle when you don't know where to look. Had experience with it in early modding. XML is just a strict markup built on visible logic.