Yes, otherwise engines on those things are totally pointless.

Yes all probes use turns from the player. So too many probes and you might find yourself unable to do anything until someone kills a few of your probes.

But suppose you put all of your resources into making insanely powerful probes. Then you send tons out and stay at your planet, wait, and watch. Obviously I don't excpect that to actually happen (imagine how bad that would suck if you invested ,say, trillions in seeker probes only for your enemy to thwart you by switching to a pio) It's an interesting thought though. And, ya, I wish I could afford photo shop, then I could make a really cool sig. Sadly, I'm stuck with the HP Image Zone crap that came with my printer. I'm working on a nice collage of dictators though, so it's not totally useless.