this must cause havoc
! I hope I fix all those errors!

always a good idea

with new makros \secsob and \consob

not man-ifold!!

finally found something

in german and english, so I need both languages in the preamble

I expect to write a lot of them and I do not fancy writing a lot of \frac and search for ∂ on my keyboard

more professional?

this way I always know which version someone commented on if they comment directly into the pdf or the printed version

better solution would be to avoid / in usepackage:
https://tex.stackexchange.com/questions/31925/install-package-in-subfolder/31950#31950
but I didn't find how to set the env variable TEXINPUTS in .latexmkrc