I have a 4 mph pavement scooter (which folds into the boot of a car - allowing me to go on days outing with family). Also have a smallish electric wheelchair, using which I can go on buses, trains, etc.
I have used a scooter for several years now With it I can lead a life outside of my home, gives liberty and independence and a social life. My wheelchair means that I can, totally by myself, go on bus rides, and use trains to visit friends and my children.
It did take me quite a long time to learn to use both of these. Yes, they are easy to use, but controlling them and understanding them takes experience. IN those early days, I did misjudge things, and act instinctively (for a car not a scooter) and had a few accidents. Fortunately none very serious. But as years have gone by I feel I very competent, and try to be extremely polite. Any time someone steps out of my way on a narrow pavement, etc. I make a point of saying 'Thank You' to them. Go pretty slow when amongst crowds, and expect small children not to notice me and to run in front of me.
My wheelchair is slightly slower and less manouverable than the scooter. I do not feel as safe on this, but thank people in buses as they often have to wait for me to get it into wheelchair space before the bus can move off.
Do think that there needs to be a period of proper training before people are let loose with one of these scooters, even the 4 mph ones, or even if some sort of good booklet could be produced reminding people on them how they need to be polite and 'give way' to pedestrians (not the other way round as a small minority of scooter users seem to think).