Sadly there isnt a master thread although if Skull-1, KingNor, Zanderwitaz, and co want to get together with me Im sure I could come up with a webpage for one. May be then they could post it on the MW main site and attract some new 1/55 nuts.
As far as where to start ... There are so many things you can do I supose that a good point is Skull 1`s A Stance mod its easy and fairly quick to do and is a major improvement., From there you could do the Swing arm mod, this cleans up the nose area on the valk, then do the foot mod to give the more Anime acurate slatted foot with pannel lines at the bottom That mod is acheived by various methods and is easy.
Once you go from there you can do this arm mod and then things like the retractable hand mod and some anime corrective cosmetic mods.
As Im sure your aware Skull is making an "Ultimate modded 1/55" but he has done this before and everytime he `s almost done he thinks up another great mod to add to his list
IMHO what we need at MW is a thread area dedicated to mods of the toylines and also some web page action too.