Mac, that is a very good point David made about coming back 4 times but if you include Ireland and also include "life", you never know when you are making it back so make sure you do what you can do and I appreciate the leg issues on your part.
Another comment regarding not over doing it, one thing I noticed on my 4- 2 weeks trips to Scotland/Ireland, I never once woke up without the excitement of I was going to play another round of links golf. I dont think I would get that in NA over a 2 week period. Everyday was a new adventure and i was just itching to get going. And I like to drink with the locals in the pubs and woke up some mornings feeling pretty hollow but the call of the first tee was greater than the pounding head.
As for relaxing on your drive to Askernish, try and relax and let me know how that goes. The A series roads are great and overall I found Scotland has wider roads than Ireland, but the remote parts require attention with the stone wall lined roads. One thing you will notice is the standard wave from oncoming motorists, they all have their hands at 10 and 2 and just lift their left index finger to wave, even the locals are afraid the take their hands off the wheel.
Enjoy the trip Pal.