I would love to play this game more with harassing and less with massive fleet-to-fleet combat (not saying fleet combat is bad, just that I would like to try some harassment). However, I really don't know how to make it work. My first thought would be Vasari with Marauder accompanied by some siege, using the speed-boosting ability to run if any hostile fleet comes by. Beyond that, the only thing I've been able to do is make people jump their fleets around a lot by feinting at different locations in their empire. That's annoying, but it doesn't actually do any damage and is rather time-consuming for me. Thoughts?
You're incorrect in your conclusion if you believe that it doesn't do any damage.
Every population you're killing, is less credits in the bank for the person you're harassing. Credits are more important than Crystal and Metal combined.
(Because they BUY crystal and metal when you need it the most.)In the early game, if you're rushing as the Vasari.
Try to sneak in a Siege Frigate into his Homeworld, and drain it's population, as this will hurt his Pocketbook the hardest. Follow it up with a couple squadrons of Light Frigates, Long Range Frigates and a Capital Ship, hitting one of his frontier planets. His main fleet will be split, and far too busy at the Home-world to defend the frontier planet you're hitting, leaving the remainder of his fleet as easy pickings.
If there is no remnant fleet, drain that planet's population too, and move on to the next frontier planet.
I guarantee if you succeed in getting his Homeworld's population down to 0, and destroying at least half of his fleet - he'll quit when he realizes that he can't afford to replace the ships you've destroyed to defend his frontier planets. If he doesn't quit, just mop up his forces, destroy any frigate and capital ship factories, and keep a siege frigate by every planet to keep the population at 0.
Economic Warfare is rough.