Tallen ... remember we are MERCS not industrialists or entrepreneurs. Let the Eve Industrial Mongols create the stuff. All we need to do is hold them for ransom. This means taking over a POCO and charging tax on every shipment that goes through , with the added bonus of protecting their POCO from other SCUMBAG Mercs. Walla we have passive income without getting your hands dirty in PI.
If you want to be an industrialist ..then play Eve its an awesome game.

Us Mercs we do our talking with bullet spray ...

For those who don't know, Planetary interaction in EVE is where pilots drop command centers on planets, and then places buildings for resource acquisition, refining, and manufacturing. These goods are then sent back into space and sold on the market.

Can we just make planetary interaction to be far more Dust oriented? The resources it collects can still be managed from EVE, but the control of the area, and a share of the profits through taxes should be with mercs on the ground.

Make each district an actual area on the globe and only with permission or a tax can someone place buildings on it. This will make certain resource rich areas of the globe have more lucrative districts than others. It also means harvesting resources on the edge of a district can warrant aggression, as it will inherently harvest from nearby districts. This means a lot of contesting over resources.

More resources somewhere else on the planet? Lets negotiate to have a suitable tax and yield amount to the district owner. Or someone could hire a DUST merc corp to attack and take over the district and give them full benefits.

Does it need to be everywhere? No, start in Molden Heath, give a bonus to those who control the district they are harvesting from, and a penalty to non controlled ones (a penalty in yield and equipment taxes). District taxes on equipment, can be set by the merc corps, either raised to increase profitability, or lowered encourage more settlement for PI. The goods harvested and manufactured are still technically within the control of the EVE pilot, but having poor relations or hostile relations with the district owner can warrant the district owner to take certain actions.

A) Heavily taxing equipment in controlled territory, essentially setting up martial law. EVE players can still mine for resources, but the mercs get a huge share of the cut.
B) Seizing ground equipment in the district, making it unusable by anyone, possible handing over to other EVE players(ransom, or gifting) for their use.
C) Destroying equipment. This can warrant a new game mode, or mini game. Instead of simply seizing it, if a DUST corp wants an asset out of their district, in order to protect their districts resource acquisition, they can choose this option.

If they are friendly districts they may be able to increase CPU or PG of a district to supplement the capsuleers.

I still am unsure if I want building equipment in other districts to be outright prohibited unless given permission. I like the idea of leaving it free to place things anywhere like it is, but with more merc control of districts, making building in unfriendly lands a bad idea.

Now this will not go well with many PI people in EVE, but most are doing PI on the side, and this only limits their options in merc contested space. When the mercs move to new regions, the rest of EVE will have to accept that the ground belongs to those who fight for it. The PI economy will still be EVE oriented, but owning a district needs to have a significant consequence on PI, and EVE needs more reasons to care about DUST, or there is no point in any of this.

TL;DR
Give DUST corps control of EVERYTHING on the ground.

I'm not sure if you really understands what it takes in time to run 6 pilots all doing PI. On average there is no "side" PI only PI as a source of income or as a pittance. There is no real inbetween. If a player is doing PI for ISK then there is a lot of hauling which is time intensive as haulers move slow. Often with many jumps before reaching a suitable market and certainly is not a task to be undertaken by someone who doesn't even fly a spaceship. As for PI benefits for corps owning districts I absolutely agree, but until Dust happens in W-Space or Null Sec I would say no.

Edit:
On a side note, I do feel that Null sec and W-space would be the perfect place for vets to ply their trade vs sleeper rogue drones and such as well as have corp bases on planet where they can deploy and feel secure (relatively) in their own bases and corp hangouts.