So, there are a great many unique tech's out there. Some could be stolen by some crafty spies. Having a cloaked spy ship that a scout can see when it gets upgraded with unique sensors would be interesting Think of a cloaked ship as a scout with no shields and no weapons that moves slowly to maintain its cloak. This spy ship can infiltrate a lab structure and steal a tech from the lab that the opposing player has already researched. A spy could also temporarily cause a loss of the "tech" for X amount of seconds/minutes depending upon what tech was lost. Ship abilities Shouldn't be affected. Ship production could be though! LRM spam? heck no my spy stopped that for a full two minutes! here is a breakdown of the spy tech level of each race. Advent, tech level 3 military AND civilian. Terran, tech level 4 military AND civilian. Vasari Tech level 5 Military and civilian.
Spies could also provide information on enemy research and fleet movements (most advanced tech research required)
My reasoning for the tech's are as follows.
Advent make the best spies, because they are telepaths. reading minds makes your spies really kickass.
Terran spies work well because they can pass as advent with some technical upgrades, and could wear a "suit" to look like a vasari.
Vasari spies would the be the hardest to mix with the local lab techs. Maybe they smell? They need MAJOR reconstructive surgery and deodorant to be socially acceptable. So spying isn't their forte. Plus, the vasari once ruled the universe, do you think they would stoop to copying some other races "technology"?
The stolen technology need not be as potent or as useful as the original, but it would give at least a limited capability to another race.
Vasari phase missiles could be stolen and a ship factory would be manually upgraded(these upgrades could be expensive as well, say 3k+ creds?) via credit cost to implement the new technology. The advent could then produce phase missile frigates. Or illuminators could get some phase missiles and get rid of beam weapons.
Likewise a spy could infiltrate an enemy factory(or starbase for that matter) to determine if it has any upgrades on it that would allow it to produce special ships. The spy could disable these special technologies for a long time at that factory.
Food for thought
Naturally people will worry about watering down the game by making races "seem" too much like others.
This idea is SO flexible that it could do both, increase player options and fun, and RETAIN the inherent advantages that the races enjoy. Vasari would still be tanks, advent would still be culture kings, and TEC would still be economic champs. The point is to supplement the fleets with more capabilities so that you can have more fun.
Also, cloak and dagger is fun!