My husband and I are planning a 10 day trip starting in London. We have been there several times so only need a couple days, followed by train to Edinburgh. The city doesn't look that large and anticipate a day there, maybe two; same with taking the train to Glasgow and spending a day or so there. Undecided if a bus/ferry or air travel is the best way to get to Belfast where we would like to see the main attractions before taking the train to Dublin and spending a couple days, including a trip to Galway.
I know we haven't included the Highlands, and would appreciate any input from those who have taken such an itinerary.
What you're describing is a hop-around itinerary that would not be to my personal taste, but if it's what you'll enjoy, more power to you. I would suggest flying from Scotland to Dublin. There are frequent and cheap flights from both Edinburgh and Glasgow.
Just be aware (we weren't on our first time) that when you land, you'll be loaded from the plane onto a bus that will take you across the tarmac. Also, when you leave Ireland for the USA, whether you fly out of Dublin or Shannon, you must go through "USA Pre-Clearance," which takes some extra time, so be sure to arrive well in advance of your flight's check-in time.