You won't find it listed that easily on a chart. Nor is it easily categorized. In the core rules it's listed with scarcity. The only other qualifiers are magnitude and craftsmanship. Certainly scarcity can stack with the other two. Still, you have to ask yourself what the results are applied on an individual basis. A BC archeotech plasma gun would gain the quality "doesn't overheat." This doesn't strike me as unbalanced, nor as unreasonable. Acquiring a BC archeotech Modified Jovian Drives that reduces the size by 1 after having already reduced the size by 4 seems like the act of a munchkin.

So, like I said, apply on an individual basis.

BTW, I simplified the process on my own acquisition charts by listing archeotech under quality. Players can approach me, on a separate basis, to ask for that BC archeotech plasma gun that doesn't overheat. That shifts the onus of research to the player instead of placing even more work on an already overworked GM.

I've just kicked off an RT campaign with my regular group and the "freedom" thing is certainly an issue, and one i had to deal with many moons ago when running WEG d6 Star Wars.

They way i've dealt with it here, is to put the PCs into debt with a more power RT "Admiral". They therefore begin the campaign in the admiral's fleet, taking instructions while they work off the debt. This means i can exert some control over what they do, but they still have freedom in how they do it. As the campaign develops and they pay off their debt, we'll all be a lot more experienced with the game, and the PCs will haves loads of "loose ends" to follow that i'll already have mapped out. Unless they go completely off base once their debt is paid it should work out!