A few ideas and suggestions for skyblock!
DONT MAKE THE ECONOMY FOCUS AROUND AUTO CACTI FARMS
The amount of skyblock servers out there, where having an afk auto cacti farm is the best way to make money is unsettling. Yes you SHOULD be able to make money from them but, it shouldn't be the best...hell it should only be semi decent at most.
Please, i know you despise crates with a passion but, include them in skyblock, minecrax/spawner/enchantment/donation ones..even if just a carbon copy over. But maybe switch some of the minecrax/survival rewards out for skyblock style prizes. Stacks of dirt/cobble. sand etc etc.
If you use the right skyblock plugin, it will come with a minishop of sorts, if not add a gui shop in..and create buy/sell prices for many common items such as blocks/plants/mob loot etc etc. But do not add everything that a player can possibly gain, save some space for players to have to use the /ah to sell items to one and another.
Death by void should honestly mean loss of items, so no keepinventory. But consider having a bit of compassion and setting mobGriefing to false. Atleast in the overworld, to stop creepers taking out blocks from underneath you and destroying your day.
If custom enchants such as rejuv/flight are to be available in skyblock...make them rare...even more rare than on towny...everyone online owns a pair of flightboots by now so it won't be long before their value drops.
Donor perks and ranks
Having a ranking system that unlocks commands and perks within skyblock separate to towny would be cool. But keep it on a separate ladder to donor ranks and perks. Save /fix for the final free rank and /fix all a final donor rank perk. rank ideas: Seedling, Sprout, Tree, Mighty Oak, yggdrasil (yes i know all tree based...i dunno why XD).
Donor ranks can be, Harpy, Griffin, Manticore, Djinn, Dyeus (all mythological beasts of the sky, and finally god of the sky)
- Auction house ofcourse, for selling between players.
- oregerator, Allows cobble gens to generate ores as your island levels up the ores rarity can increase https://www.spigotmc.org/resources/ore-generator.41222/
- slimefun and some of its addons such as exotic garden, even though its majorly buggy, if a lot of the dupe items are disabled...can make skyblock a fun experience. (disabling a LOT of the tools/amulets/electrical things until bugs are fixed)
-Greenhouse plugin, allows players to create greenhouses for various mobs/plants...all explained here https://dev.bukkit.org/projects/greenhouses
- mobstacker, this is lower on the list as its a bit touchy with some people but, if you have 30 people on islands with 30 spawners each all spawning mobs..its going to lag..mobstacker will fix this issue, and if the players set their spawners up properly to auto-kill mobs (but that rarely happens). they have them all spewed in a small area to kill at their own leisure.