not sure what part you were talking about, i am not a master composter so you're getting to the limits of my experience
but on the shreading leaves,...
i plant directly into my final pot, it works and is simpler
but you seem to have the basic idea, i'd guess the starters probably would be good for 2...
if you're going to use pots outside, then you could get away with a slightly later start
most plants will fill in a pot/bucket with roots quite fast...
cut trees could be a red flag, depends on how long ago they were cut
add garbage and that does get a little sketchy, spots unvisted by people aren't...
40 plants is a large grow, it can be done obviously, but at that point you would likely want to haul a soil load by some motorized vehicle
40 pounds...