Condition 1)- The aircraft will not leave the MCP alt in V/S. It will revert to Alt. IF the MCP is ABOVE the actual altitude, the aircraft WILL descend in V/S.
Condition 2) Not sure what you're getting at- if the aircraft descends in V/S to the altitude set in the MCP, it will capture that altitute. There is no relationship between what is set as the MDA and the behaviour of the AFDS.