Wow, you guys got a big group. I've heard longboarding is huge there, i heard they held a few longboard dance contests out there not long ago.
You can buy risers for the longboard trucks that absorb some of the vibration. They are little rubber pads that go between the truck and the board. Wheel choice is also important, hard wheels roll a bit easier if you're on a smooth road, but soft wheels make those rough roads a lot easier to handle. Boards with flex to them are also great for rough roads, like the one im riding which is made of bamboo.
I've also heard of a few trucks with a form of suspension being made recently, but have not tried them myself yet. Admittedly i am road picky, so i choose my route based on the smooth roads available, rather than just the shortest distance.
Thanks for that little video, so happy to run into a fellow rider already on here.