You can have this wall redesign for free:
Step the first: Remove all walls from the game. Don't really care how you handle the inevitable cries from people wanting their NIC back but this implementation cannot persist into the age of PBS.
Now we lay down a very basic framework for PBS.
Influence:
Outposts give influence/control in a radius around them. This area increases with the level of the outpost. Structures can be built within this area.
Structure Footprint and Slope Tolerance:
No structure can be built within 3 tiles of another structure. Structures have a slope tolerance. If any one tile that the structure occupies exceeds this tolerance then the structure cannot be placed. Basically large buildings need very flat areas. Small ones can be built on fairly steep slopes etc.
Power:
Power Generators are structures that must be built. They are solar powered (anything else doesn't make sense and I'm sick of refuelling from managing POS in Eve) and generate an amount of power relative to their physical size. All power is distributed via Nanotechnology (nanotechnology is like saying magic) to any structures that need it within the influence area. All structures except Power Generators consume Power.
CPU:
All structures consume CPU except for SuperComputers. Supercomputers generate Terraflops. I think you can see where this is going.
Barrier Nodes:
These are the new walls. They use a small amount of CPU and a moderate amount of Power (Something like automated turrets might use a lot of CPU and Mining rigs may need lots of both). A Barrier Node is a 1 tile targetable structure with the same slope tolerance as a light bot. Basically they can be placed almost anywhere and be shot by everybody.
Each Barrier Node will emit a plasma barrier that prevents bots from passing through it. This barrier can only be connected to one other Node so no T-Junctions can be formed just lines. You can ring them around if you want.
When a Barrier node is destroyed then that section of "wall" will disappear. If there is not enough power or cpu to run all the structures then structures will offline (either in order of largest consumption to least or at random if there is a stalemate).
Security:
If any structure starts to take damage then all members of the owning corporation will be notified via a ping on their radar.
The structures can be "built" using the plant growth system (IE progressing in stages and can be accelerated) but I'd say that's as far as the similarities with plants should go.
Naturally you can fit a great many different structure types into that framework including gates, turrets, mining rigs, harvesters, factories etc.
