Hello! A lot of good ideas here! I'll go ahead and jump right in.
The Exchange - 3 new blocks, 1 for Trade Guild Stations, 2 for ships
- Exchange Network Core for Trade Guild Stations only, acts as a "node" that reaches out to other nodes within a set distance and tracks resources and missions/contracts from neighboring nodes. This will establish trade routes between Trade Guild Stations, and if say less than 3 nodes are connected, then a new contract is made. A contract for a player to build a Trade Guild Station and expand/establish trade routes. Then limit active nodes per Trade Guild Station per system (so if one gets destroyed another in the system can take over). Each node could also produce income like a trade tariff to the faction owner of the system
- Market Computer and Communications Module for ships. The Market Computer will be an interface that "taps" into the market when in short range of a Trade Guild Station node and the Communications Module increases the range. This block will also show coordinates of "active" nodes to show you the trade routes nearby. Now these blocks should only be available for purchase in Trade Guild Stations with a good faction standing. The other option is to happen across a Trade Guild ship and destroy it to hijack the Market Computer and Communications Module which you can then use to track trade routes and Pirate them.
Contract Insurance - I think the simplest way to prevent griefing would be to require Contract Insurance to be paid by the person accepting the contract. This could be a set percentage or something a player sets. If the contract is violated the credits put down for the insurance is then used to make a new contract.....a bounty on the player's head!
Thanks for reading and all the good ideas already in this thread I've tried to build on.