To earn the Shadow Chancellor achievement is rather easy this way. You simply place 1 riflemen on each side, close to each other but not too close that they can shoot right away. You start the match and take over the Rifleman you need to have win. Simply rush the other rifleman and hit his crotch with a hand grenade. Don't forget to bob and weave! do this 50 times. Takes a long time but is WAY faster than actually earning it.

These two are really easy and related to earn. They go hand in hand.
1. Go Sandbox 2v2, unlimited time and cash, and a flat map.
2. On one side, place 4+ Barracks (not enough to crash your computer). I used American Barracks. Fill all the barracks queues with Flamethrowers, they are the only infantry that cannot hurt your tank (but be cautious either way).
3. On the other side place a single flame tank. I used the Italian one. Start the match and take control of the flame tank. run over the flamethrowers until you have earned all three "watch the road" achievements, finishing with "Really Really Watch The Road".
4. Begin torching the flame troops until you earn all three flame achievements, finishing with "Pyromancer". this may take a long time.