If the mod team needs help, they will request it.
Comparing online demons to these levels, the "extra" stars you get past 10 stars is only 22 - roughly the same as you would get for beating 2 extra demons. So beating all 8 of the levels you suggest except xStep (only 10 stars) is roughly equivalent to beating 10 demons. But doing all 8 of those levels in a row is over 10 minutes long, so unfortunately it takes longer to do then just beating 10 shorter online demons.
yeah most of these categories would eventually devolve into demon speedruns unfortunately. even getting 500 stars fastest is probably just beating 50 demons in a row, as no other strategy really comes close to that (~10stars/minute if you don't die)
only other fast-star methods that i can think of are all significantly slower (10+ star official levels, demon map packs, etc.)
If you ignore level loads, possible speed skips, and menuing, the combined time of all map packs is 4:24:04.
good luck.