Is walking from school included as an exercise?

Well… That depends! For how long do you walk for? I dont think it is enough, due to other muscles of your body do not get moving with walking. Maybe add a hand session and some abs and squats amd you will be good to go!

Yes. Walking of any length is an exercise both physical and mental. Physical for burning calorie and mental for thinking while walking.

If your regular means of transportation is not walking, then walking instead of taking the bus, train or a car is definitely exercise.

Yes, walking is considered excersise no matter how slow or fast you go. It is better if you walk longer distances so you burn a little bit more calories than if you just walk for 8 minutes

According to my understanding. Exercise means heart rate needs to remain at 160bpm for more than 15 mins. So in this case it is not. But, in the other hand, by walking can include huge amount of muscles movement, which indicate walking from school still a work out for our body. So despite walking is not quite close to the definition of an formal exercise, I'll still consider that can be part of the exercise routine.

I'd say so. Especially if it is at least 15 minutes walk away. Walking is an easy, free way of getting fresh air and exercise.

Yes, I understand that part of the exercise routine is building on whatever you already do. This makes us more likely to succeed

Yes if you try to walk somehow fast than regular and for 30 minutes will be perfect ( this is an opinion and not a professional recommendation but if I was you it will be perfet for me and significant for my health )

Yes. Definition of exercise according to Google;
1.

activity requiring physical effort, carried out to sustain or improve health and fitness.

"exercise improves your heart and lung power"
So if your heart is pounding when you walk home or run then it's exercise. And playing after school with friends running around also counts as exercise. But remember that the best exercise is when you are having fun, flex your emotional muscles too. So laugh and cry and be happy. Emotional exercise and mental exercise are just as important as physical exercise. May the force be with you. Peace and good tidings to you