For PvP/PvE and general market/use; the ability to construct/own and mange city's/buildings would be a very good feature to add.

Ideally walls, housing (personal and industrial)  made and upgraded by a person or corp with the ability to even set taxes for visitors  (*as in a created refinery, upgraded to give amazing refinements and thus promoted around the chat channels or corp channels  would draw agents to it as opposed to the NPC refinery. Then any agent whom used it could pay that tax to the corp/agent that owned it while still receiving much better refinery results then the NPC refinery). 

Could also tie into pvp very well. Implementing rules for destruction of said walls/buildings and such, as it's key in non protected islands but other wise very very good to have as a feature plus a massive massive need for economy and market as each thing would need to be mined, then produced then sold then maintained, great for the market all around.

Examples could be:

*Corp storage building
*Corp teleport building
*Corp Refinery
*Personal home/storage
*Personal refinery
Etc.

Cost (as in the original materials + cost of production) should be heavy, causing a lot of market growth and support.

Personal vr Corp would clue in to taxing or subletting (allowing people to use your teleporter or refinery (a thing that the personal version should not allow) and thus cost much more initially.

Upgrades would then be an other package with it's own costs of both materials and production allowing an already built item to have improved abilities (lower % of waste per example in a refinery).