0.01% is going to mean you aren't building anything at all! What's the "political modifier" mean, fellow Aurora experts?
It's a malus based on a colony's Conquered/Occupied/etc. status, plus I think maybe unrest modifiers? Sounds like a colony that's in full revolt with no troops to keep order.
So, Bay12ers, forumites, and Aurora-players! Lend me your ears!
What is the difference between a commercial and a military jump engine?
The former is brought to you by Markus-Price Jumpdrives! Remember, you can't spell jump without "you" and "MP"!
Seriously though...commercial drives are ten times smaller than military drives (or to put it another way, the jump capacity of a given drive tonnage is ten times larger for commercial drives) but only work on commercial vessels. Military drives, conversely, only work on military vessels (and by virtue of it being a military-grade component, any ship with a military drive is a military ship).
Commercial drives have no maintenance requirement, while military drives do. And being a fairly significant part of the ship's tonnage, it's one of the more common parts to break if there's a hardware failure.
Which is why it's common to build heavily armored jump tenders and leave jump drives off the bulk of your military vessels. Downside, of course, being that if your squadron's jump tender is destroyed (or the jumpdrive destroyed, at least) the whole squadron is stuck in-system.