The settings in motor turning are 800 rev, 600 vel, 50 acc. At this speed, the y axis which is very heavy, seems to shake just a little at an abrupt stop. The other two, could be set to go faster
Well it looks like you are getting there. Its always nice to see another machine come to life.

Now when you command the machine to move say 200mm does it move exactly 200mm or something different.

Try putting G1 X100 f300 into the MDI and press enter. The X axis should move 100mm

Re the earth rod For a test you could just knock a metre long metal rod into the ground and connect it to the incoming mains ground. If it works then get a copper coated rod.