I've gone to read reliable texts to educate myself, and Outlander only missed a few details (Sir John Cope for one). The Skye Boat Song does lead a few to trad folk ballads, however. It furthered my interest after I found a small niche of interest in Scottish history.
As for the portrayal of Scotland, what is missing? I've never been there as much as I'd like to one day... Certainly I've met and had a few Scottish teachers, but that's only a small insight into life in Scotland. What's not accurate?