Here is a list of ideas for donator perks that would be compliant with Mojang's EULA. Feel free to add any additional ideas in the replies section!
Donation goals mass perk
(i.e. when enough money is raised everyone, donator or not, gets money in-game or a claimable gift at a warp or something)
The following are not EULA compliant (according to Mojang);
The following may not be EULA compliant, please elaborate on what you mean;
I'm too sure how I feel about these;
That leaves the following ready to implemented (removed already implmented perks);
/ptime and /pweather are cosmetic as they only show up on that player's screen
They do not influence the whole server / gameplay. Ex. ./ptime night does not cause mobs to spawn if the server time is day
Donator houses would be in a claimed area and would simply be decorative, i.e. you could say you owned the house but you could not gather its materials
I would love to have the particles that are the book shelf one in multicolor, like the one in Wyn-- um you get the idea.
@lela_null: https://www.spigotmc.org/resources/particle-effects.534/ was the plugin I was going to use, however we do need a donation as I can't afford it right now.
Ultra Cosmetics seems like a very good plugin however, I will look into that.