Add Guardians to /spawners
This seems pretty self explanatory.
Add /fix for $10000 to MCMMO II and Star
This would be a fairly simple addition, and would create a lot more incentive for MCMMO levelling or purchasing a rank. I personally would be willing to pay $10 USD for this feature (along with the other Star features) and I think others would be as well.
Make Slimes, Magma Slimes, etc. stack
So many players are irked by these not spawning, and, although I've already made it through these levels, it took an incredibly longer amount of time to complete it. I finished the levels that follow slimes almost 10 times faster than slimes, which doesn't quite make sense.
Move Guardians to a later (aka reorganize the levels to match the economy)
It is SO annoying that the $1.5million mob (and the hardest one to grind) comes before Magma cubes and the like. I understand the plugin is probably not customizable, but if possible I would seriously consider contacting the developer as it really is incredibly annoying to have to deal with that.
Add /craft and /trash to MCMMO and Donor ranks
Honestly, I would use these so much you don't even know.
Add ink sacs and spider eyes to /sell (because why not?)
If you have a squid or spider grinder it is very inconvenient to have to throw out half of your drops. and there's really no reason to not have this?
They seem very random and unorthodox (blazes and skeles are cheaper than chickens and sheep?)
Make sell wands craftable
/selling 20 dubs of drops sucks. Because non-donors can't use sell wands it would donating more desirable (because the incentive isn't very high right now considering you get like 1 sell wand every 4 days) but also not take away value from Cosmic's /sell all.
Okay thanks for coming to my TED talk