Hi again karjoka8,
The first part of your new itinerary looks better. If you're visiting Blackness Castle, and are Outlander fans, Midhope Castle (Lallybroch) is only about 5 miles up the road.
Anyway, if you do continue on to Skye on day 4, and are planning to drive to Elgol in the morning of day 5, you should stay in Broadford, Breakish, or Kyleakin. If you stay in Portree your first night on Skye, it's about an hour's drive back to Broadford, then 45 minutes to Elgol. There are a couple of good hikes out of Elgol, and one to Camasunary from Kirkibost. However, if you were thinking of taking the Bella Jane to Loch Coruisk, I'd advise against it if you want to have time to drive around the Trotternish Peninsula to Uig, and then on to Dunvegan. Last entry to the castle is 5:00 p.m., I think.
Day six will find you viewing the West Coast through the windscreen. As you said, it's 160 miles, give or take a few, from Dunvegan to Ullapool, and then if you're turning and going to Inverness, that's about another 100 miles, depending on which way you go. Then you're going on to Aviemore. Ullapool to Aviemore is a good four hours, and you're going to need to stop for food, petrol, and toilet breaks. A lot of the roads you'll be on will be two lane, but you may still encounter some places where it narrows down to one lane with passing places.
Day 7 - Aviemore to St. Andrews. You have a long way to go, but this can be done in a day. A9 past Perth to Bridge of Earn, then the A913 to Cupar and the A91 in to St. Andrews. Or if you're going by way of Ballater and Balmoral, overland to the A93 at Ballater, then the A93 south to Blairgowrie, the A923 to Dundee, cross the Tay Bridge, then the A914/A919/A91 to St. Andrews. However, that drive would take so long that you'd have little time to spend in St. Andrews.
The one thing that you have going for you is that you're traveling in June, so there'll be lots of daylight. Days five, six, and seven, however, are going to involve a lot of driving. I don't want to discourage you, but just be prepared for long drives and long days.
I don't know how many of you are traveling, but if you're stuck for accommodation near Dunvegan on day five, the Skyewalker Hostel in Portnalong may be a possibility. In addition to dorm accommodation, they also have en-suite twins and some 2-3 people yurts.
Best of luck!