If I understand, you two alternatives are
1. Import taxes
2. Plant-bound items
Well, I'd love to here your explanation of how those taxes would work. As for planet-bound items, that is problematic. Does that apply to all stacakables, even those that are lootable on other planets? What about items, both (L) and UL?
Please don't... making it as you didn't understood what I mean.
Start with your country and ask your govern how they do and why, visit some institutes and university and after that go look how other countries solved it lol.
In EU PvP space do not defend local planet economy as big traders use motherships to move big quantity of resources and items without any risk.
Our botany is not at that high lvl to be able to know anything about Plant-bound items
I don't know on what all could apply planet bound items or resources that is on MA and PP to decide but maybe to try an example.
New planet with noob hunters, miners and crafters then come reseller dude and start selling Calypso mining amps.
Ofc those amps were crafted from high skilled crafters, with PB QR 100% and with cheap resources from uber miners and hunters. It don't help local planet and its players at all but destroy local economy.
Having at disposition imported cheap amps instead to use own don't help local hunter, crafter and in very end probably don't help to local miner too - he can sell his ores underpriced to same interplanetary reseller as only choice.
All economy end just in selling and buying from Calypso.
Is not local economy or partially opened economy but fully opened market to Calypso predators without any defense.
But if PP could apply additional fee or tax on that Caly amp miner would still have freedom to chose between amps from local crafters or more expensive one from Calypso. Is not greed, is called defending local economy.
And is not just an amp, is just for example, could be fap, gun, clothes or resource and so on.
Space in no way defend local planet economy so all crap MA said about it have very low value.
PVP lootable space defend pirated and motherships economy only because their business is based on existence of lootable pvp.
So why space is PVP - because MA needed excuse to collect money by selling motherships and invent mode to use them and piss rest of player base because using mothership without having other safe way look like an sort of extortion.