A.  Walking on a treadmill, whether manual or motorised will definitely aid in reaching fitness goals, and can replace the morning walk.

Although there may be some differences, the motorised treadmill does score over the manual one for many reasons: the motorised treadmill is smoother to walk on and has many other advantages like settings for uphill walk, speed settings, and calculations of calories lost (based on input of your own weight entry into the machine). But that is not to say that a manual treadmill will not have any benefits.

On average, an hour-long walk will spend about 200-350 calories per hour for a person weighing approx 60 kg. But it’s also a function of the pace, the body composition of the person, and the walking conditions.

To answer your next questions will require more information from you and your goal.

Your reason for walking:

If you are looking for health benefits:
Walking 2-5 times a week, for 30-60 minutes at a time at a pace which is slightly more than what you can take, walking at the speed of covering approximately 5-6 km/per hour.

If you are looking for weight loss:
3-6 times for 30-60 minutes each time or broken up into chunks calculating the same. The pace can be slightly more than what you are comfortable with, interspersed with short bursts of high intensity for 1-2 minutes and double the recovery time.

If you are looking to boost your stamina:
3-6 times with high intensity workouts.