An answer to some of your questions may be found at:
Doug Willett's site treats linux and lxde in a Mint context, but there is a lot
in common with the current lxde-oriented Knoppix.
I doubt there is a 'linear' approach to be had.
Enjoy the non-linear joys of trial and error.
And welcome to the forum.
edit: I note Doug's site has apparently moved since my earlier note.
TUNING LXDE is now at http://douwil7.100webspace.net/linux/Tuning.html.