Need some help deciding where to focus our time in Scotland in August. This will be the first visit for both of us, and we hope to come back again when we have more time. We will be in the Lake District of England for a few days prior and plan on taking the train to Scotland. Normally we'd want to spend some time in Edinburgh, but due to the art festival/peak tourist season there in August, I'm thinking we should avoid it. So I'm wondering if we should save Perth/Fife for another trip when we could tack on some time in Edinburgh, and visit Shetland instead? If we did Shetland, we'd take the train to Aberdeen and fly to Lerwick, so we'd at least get to see some of the Fife area along the way. We have 6 days to fill (including train from England and flight back to London).
I don't love the idea of driving in the UK, but am guessing in the rural areas there is no way around it. Is there adequate public transit between towns, or is a car rental absolutely necessary? I could deal with driving in the countryside if there was no way around it, but I don't want to in cities/traffic.