No, because when extended, you lose the cooling effect and the machine can shut down.
Yes, an internal tank that can be emptied via the drain plug. (The internal tank cannot be removed.)
Simply unscrew the plug at the bottom. Feel free to tilt the machine slightly over a floor drain.
No, this can damage the machine.
Especially in winter, when the air in our homes and our workspaces can be extra dry. A humidifier simply makes the air more humid. A person who feels dry mucous membranes has asthma, allergies, or a respiratory infection can use a humidifier. Many also experience that their mucous membranes are not as dry when they add moisture to the indoor air during the winter. If the humidity is below 40-50% RH for a long period.
When the relative humidity is below 50% RH, it is recommended to use a humidifier. Normally the relative humidity is 15-30% during late autumn and winter, so it is mainly during autumn and winter that a humidifier should be used.