Cham - You can only research one technology at a time so to rank up a technology you already have means for going researching new technologies. (I still habitually call them skills but technically they're technologies)

The stealth penalty reduction is relative so 78.5% of normal speed would be the maximum speed of rank 9 cloaked ships.

Currently you can kill yourself with a blackhole, I suppose we should do something about that but it would be pretty funny to an outside observer.

Spar - Yes, it's a modifier to a base stealth / detection value.