So I probably wouldn’t add all these features to this plugin because I think they may be a bit out of scope, but I could certainly write some companion plugins to add some of these 
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Min-/Maxrange for a Graveyard - This is an idea I’ve been toying with for a while know, the issue is it does add to the complexity of calculating which Graveyard the player should spawn at (i.e. with an overlapping radius), but the real issue is how to handle the case where the player is not within range of any graveyard, what happens then? I’m open to suggestions
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effects after respawn, like visual and potion - Companion plugin would probably be best for this, I’ll add it to the list!
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choose weather or not keeping items / certain items - Vanilla Minecraft actually has this feature if I recall, however if you want to only have certain items stay you would need a plugin or use the curses
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items will be stored in a chest at deathpoint - Companion plugin definitely, though not hard to write, I’ll look into this as well
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death costs money - have to figure out the case where the player is broke, in that case would they not be able to respawn?
In the meantime, I think this plugin may suit some of your needs.