Really if the player had sent an attack the recycler's should have already been flying to make the target soon after attack. Waiting until the attack had actually happened then using the planet displacement he had obviously intended to do it if his recycler's weren't inbound to the attack point before the attack run was sent. If you look at it the planet was used offensively as collecting rubble from the attack is to be seen as a offensive action. To me the GO who responded is correct in his decision.
It would be easier if you removed the current ruling about displacement and replace it with
A planet displaced and moved is put into vacation status for 48 hours. Making the planet unable to be built on and any flight action not able. Virtually that planet is in vacation mode. Which would mean other player's wouldn't be able to spy or take any action against that player. This method would stop all illegal actions against any of the rules within the game.
I see 48 hours plenty of time for someone who the planet is moved closely to. To prepare for when that planet becomes active. 7 Days is way to long.
If you did something like I said just above you could possibly then make planet displacement purchasable item with Urplasma. But restricting the planet displacement for the displaced planet with a timer before it can be displaced again.
You could also think about turning planet displacement into a tech as well.
Energy Tech + Blackhole research
Unsure to what levels to achieve energy displacement engine.
Energy displacement engine is a building that acummulate particle's needing 100% to activate displacement.
By going with the 48hr VM mode for displaced planets. This would become possible.
