Need help with only 8 days to work with

If I were you, I might just stay in Edinburgh and take some tours to those places, although Stirling Castle is definitely doable on your own. I loved visiting there, and you could easily spend most of the day seeing the castle and the town. Don't miss the free tours at the castle - they start at 10 am and are every hour on the hour. And the town of Stirling is well worth seeing, too - lots of gorgeous buildings and wonderful history. I got there by train from Glasgow (it's also an easy train ride from Edinburgh) and walked up to the castle, but there are also taxis available to take you up as it is a very steep hill.

The most popular tours that I have read about on this forum are Rabbies tours. I have not taken one but by all accounts, they are a very reliable touring company. Here is a link to their tours originating from Edinburgh. As you can see, they offer anywhere from 1-3 days up to 20 day tours. And certainly Skye is on their itinerary. https://www.rabbies.com/en/scotland-tours/from-edinburgh

That said, there are certainly other islands that are enjoyable. I was there for 3 weeks in May of last year, and visited Skye, but also visited the Isle of Arran, which is a very small island and easily doable in 2 days. Or the isle of Mull, which was absolutely wonderful. I loved staying in Tobermory and especially enjoyed taking the ferry over on a day trip to Iona. If your husband likes history, I would imagine he would love Iona.

I had to laugh at your comment about your husband reading every single word on every plaque. I definitely know people like that, lol!

I really don't think you have the time to visit all the places you mention in 8 days. Please remember that it takes a long time to drive in Scotland because of the many single-track roads. You need to add about 20% to the amount of time that google gives you. Last June we were in Scotland for 16 nights on the ground, and we visited Edinburgh, Anstruther on the Fife Coast, Nairn (near Inverness, visited Cawdor Castle, Culloden, and a few other places), Skye, Glen Coe, and stopped at Stirling Castle on the way back to Edinburgh for an overnight next to the airport. Where are you planning on staying when you visit Cawdor, Culloden, etc.? And exactly how many nights do you have on the ground? When is your trip?

We absolutely loved Skye, and the crowds in June really weren't that bad and did not deter from our enjoyment of Skye. The scenery is stunning! However, to do Skye justice, and to make the drive there worthwhile, you really need a minimum of 3 nights; 4 would be even better. We followed the On The Luce blog for a Skye roadtrip.
https://www.ontheluce.com/isle-of-skye-itinerary/

How many nights are you planning on staying in Edinburgh?

Since you didn't go to Glen Coe last time, I highly recommend visiting Glen Coe for 2 nights. We traveled with another couple, and all 4 of us agree that Skye and Glen Coe had the most stunning, dramatic, and gorgeous scenery. A major highlight was the drive down the Glen Etive Road in Glen Coe. We were very happy with our stay at the Glencoe Inn.
https://www.ontheluce.com/glen-etive-road-scotland/
https://www.crerarhotels.com/the-glencoe-inn/

You itinerary is ambitious for 10 days , especially if you don’t want to rush. Although Rabies gets very good reviews, think hard about doing a coach tour as you will be going at the speed of the tour which may be wrong for you (not enough time in places you want to see and too long in others that don’t really interest you...) You can easdily plan a good trip and hiring a car. Book through Celtic Legend for good deals and they are very well regarded on the forum

What is the attraction of Cawdor Castle? It isn’t one of the best castles in Scotland. Although it has links to Macbeth from Shakespeare, even the castle website admits it has nothing to do with the historical Macbeth... Culloden is historically important and the Visitor Centre is good but to be honest the battlefield is just a large open area. ... (If you want to see a battlefield, there is Bannochburn near Stirling where Robert the Bruce defeated the English Army of Edward II. Historically very significant and important to the Scots - they lost at Culloden...)

Begin with Edinburgh - you won’t want/need a car there as public transport is so good and parking a nightmare. Pick up the car when you leave.

You could plan a nice circular itinerary taking you to St Andrews, Glamis, Blair Atholl and then up to Glencoe. There are plenty of interesting things to do and see along the way. Return via Oban which would give chance for a short trip across to Mull if time allows, which in my opinion is equally as good as Skye! Visit Stirling on the way back to Edinburgh. This becomes more manageable as well as letting you see some good scenery. I'll leave you to decided on stops and how long for each...

If you have a car you will only be able to accomplish about half of what is on your list. I would suggest removing the more northern places such as Skye and Culloden, and even Glencoe ( really not much to see, it’s a destination for serious hikers). I agree with going to Mull from Oban, and you might also want to look at Inverary castle. The other option, as someone else suggested, is to just stay in Edinburgh and do some day trips from there. It would be a lot less stressful than constantly changing locations. You can see a lot of places with the various day trips. You might even split your time between Edinburgh and Glasgow, fly into one and home from the other.

During our limited days in Scotland this past fall, we opted to save Edinburgh for another time (we visited once 22 years ago---Castle the Royal Mile, Fringe Festival & Tatoo) when we will no longer feel like driving. We took in Stirling -stayed 1 night--castle next day; Loch Lomond enroute- stayed 1 night, Inverary Castle (Campbell for daughter's partner---skip if you are going to Blair and Glamis) + neolithic stones en route to Oban 1 night, mid-day distillery tour; Glencoe 1 night--short hike, and the drive through to Crannog Centre in Kenmore; dropped daughter off in Edinburgh and my husband and I headed south towards Dumfries area for 4 nights.

It would've been nice to be more leisurely en route but this worked for us this time---daughter's partner's 1st trip overseas so we wanted to hit a few of his Scotland mustsees (ours, too). They had already spent a week in England. We did have enjoyable evening meals in both Oban and Stirling. We would've liked to have gone to the Folk Museum, but we settled on the Crannog Centre as she and Caleb decided that they wanted 3 nights/2 full days in Edinburgh. Our family had been to Culloden in 2001 when we travelled by train. Perhaps the pouring rain added to the somberness we felt at the battlefield at that time.

So, we had a quick route of 4 nights, but we didn't attempt any of the islands, nor Edinburgh this time. Another trip we will head north, as well.

I think you could fit everything else in at a nice pace, without Skye/Islands, or take a few days there and less time in Edinburgh, no Culloden, Cawdor Castle...I wouldn't add anything if you drop Skye. Just enjoy.