To answer your questions:
If you go round a corner too fast on anything with wheels, you lean inwards to counteract centrifugal force or it will try to tip over - think of the difference between going round a corner on a two-wheel bicycle vs. a tricycle, or of a car that doesn’t brake sufficiently or a supermarket trolley pushed by a too-enthusiastic shopper. You slow down instinctively.
You also learn cross transverse slopes, where the ground is higher on one side than the other. It is the difference between walking or riding a bicycle across a slope vs. pushing a baby buggy, which tilts at the same angle as the ground and tries to turn and go downhill. You swiftly learn to follow the advice on the Travelscoot web site always to go straight up or straight down a slope, which means travelling two sides of a triangle when going up a dropped kerb - straight up from the road then sharp left/right having reached the top - rather than following the desire-line you would take as a pedestrian, covering the shortest distance via the diagonal route.
If you do find yourself on a cross-ways slope and feeling like one of the back wheels is going to lift off the ground you automatically put your foot out to the ground, which is always within reach - unlike what appears to be the case with some mobility scooters where you sit higher.
The seat is fine, much like a dining room chair with a padded seat (as opposed to a kitchen chair). If necessary to add more padding, my Heath Robinson approach would be to get a piece of sheep’s fleece, such as sold for lining baby buggy seats, cut it to the right size and fasten it with pieces of elastic underneath, like the strings that keep an ironing board cover in place. However, I found blogs by breathtakingly fat American ‘women of size’ who appear to adore the Travelscoot and do not refer to needing to add anything to the seat. The Travelscoot is designed to carry someone weighing up to 22 stones; I presume the seat padding is designed to cope!
On cost, I ordered the more expensive version with the better, lighter weight battery. You sign a declaration to be exempt from VAT on grounds of disability and the total bill came to about £1,600.
I bought the basket, which is jolly useful on the front to throw in your handbag, folding walking stick and other things you would otherwise be carrying. I have also taken the Rixen Kaul basket from the front of my now-abandoned electric bicycle, which is much bigger, and attached it to the seat post so that it sits behind the Travelscoot seat; it hangs below the seat so it will not raise one’s centre of gravity when filled with several kilos of vegetables, but the Klickfix mechanism of the basket bracket means the basket is detachable - it does not have to be unloaded to get the shopping indoors and is not in the way when needing to charge the battery.
The problem is finding one to try out before buying it, because there are no showrooms offering test drives. Ditto, you never see it advertised - awareness seems to travel by word of mouth; it is the marketing person’s dream (I know, I am one!). I discovered it when I saw one used around the local farmers’ market - the lady owner turned out to live a couple of streets away and let me have a go. From where we live in Dartmouth Park everywhere is either up or down. If anyone is in London or within striking distance I am happy to let you pootle off across Hampstead Heath for an hour or so - it goes up Parliament Hill quite happily.