So warlords bring protection to the table. Traders bring resources to the table. What do researchers bring? Why would anyone trade with a researcher? Wouldn't it just be easier to not trade with them and let them die without any RO?

Maybe there should be some kind of small bonus to research that people trading with a researcher get, per trade? Like for every trade, you get 15 seconds off your current research goal up to some limit.

Or perhaps planets trading with a researcher should get a small bonus to population growth (not that this has a big impact on the game).