RE: Clobbering Kraut Corner
If you toggle it off, you can fire or assault with the remaining movement points.
Engineers are better than their PzC counterparts, as you don't lose MP's for entering a minefield. This also makes those Sherman Crab/roller units overpowered in my opinion, as you can drive through and clear a minefield several hexes deep with a single company in a single turn.
If you disrupt the defenders of a bunker behind a minefield, you can assault it normally on the same turn with the engineers. Unless someone clears the minefield, the engineers that captured the bunker will be isolated next turn however.