Good news!
I was just able to import a collada model from MH r1955 (Nightly Build 20150626) directly to the beta grid in Second Life without Blender and it looks somewhat normal.
Feet On Ground, Z Up - Face X, Local = Global, Meter (This was actually my first try after a long time with these new options to export and those seemed to be the most appropriate and logical for SL.)
I can't say everything is fixed yet because I tried to import with skin weight only and a version with skin weights + Joints enabled and they seemed to be the same after. However, I recommend trying out all options BEFORE asking me why it looks weird. I'm still trying to find the best options myself too. For example: Your eyes are still dislocated so we may have to hide those with a full alpha texture, but... this may be fixed or not after a relog in SL.
For everyone who has trouble with the textures: Always use textures without an alpha (24bit TGA - alpha DISABLED) Except: Eyelashes and eyebrows if you use them.
Oh btw, you still use the normal skeleton, not the fitted mesh/fitmesh skeleton so sliders will only work if you adjust lengths of bones in SL. Remember that. You can create your MH doll as cool as you want but the result will still not exactly be the same if you wear a different shape than the one you made within MH... Oh, and use the betagrid for testing? Saves a lot of money there.