With which tool was the problem you describe in 1. ?
I just did a brief test with pick axe; there it worked for me as intended: https://www.youtube.com/watch?v=6vBfgo3_J1A (in the video my controller is far from the actual voxel I'm digging with the tip of the pick)
I did not know about Medieval Engineers; this looks really cool (and inspiring) from the videos I have watched. Thanks for sharing this!