These tracks should be compatible with most brands. I have tested most pieces, but not all. So if you have any problems please drop me a comment.
One quick tip: if you're printing a piece with both a road and a rail side, print it rail side down to save on support material.

for switch track I try to include every combination of connectors, however most of these are hard to work into a layout 'naturally’ so unless you have a specific application in mind i would recommend only printing the MFF and FMM parts

Doesn't Matter

Yes

All the CAD work was done in FreeCAD
All the math behind the CAD was found here: http://tamivox.org/dave/train/index.html ,more specifically the 36 degree system described there.

A word on naming conventions:
I try to standardize the file names. But in case anyone finds them confusing, I'll give an example from each batch of uploads, and explain it.

“v by 144 MFF mk1”
‘v’ says the shape of the track
‘By 144’ say the length of each segment of the V in mm
‘MFF’ says the type of connector on each end of the track in a clockwise order looking at the top of the track. In this case the connector on the bottom is ‘male’ the top left is ‘female’ and the top right is ‘female’
‘Mk’ gives the revision (or mark, hence mk) number. Don't worry too much about this, it's mostly there to help me keep track.