Toni, it's heartening to see you were happy using trains and buses. You're right about the roads being challenging sometimes. It's difficult to enjoy mountain scenery when you are concentrating on not falling down the side of one.
When I drove in the Highlands before, I'd been living in the UK for a few years so the left-side-of-the-road bit was second nature by then. Driving does allow you the freedom of stopping any time you wish and going down any road Just to see where it goes (my idea of a good time) but that loses its allure when the weather turns sour.
As it turns out, I've decided to skip Scotland. The dates were bumped to October, so the weather gets more iffy. I don't want to spend the money only to see it turn wet and nasty for the duration. Too much of a risk, for me at least, so I'll spend my time and money in London on this trip.