I've played about 6 or 7 hours total now I think and on the way have gone from level 26 to level 27. Which raises the point that I said I noted the number of my last save in Skyrim . That was pretty pointless really as when the mod is played everything changes in stats according to gameplay.
I've since found that when you want to return to Skyrim from Falskaar most characters you speak to will answer the question 'How do you get back to Skyrim?' and when you ask them they give details of how to catch a boat back there.
Presumably when you want to return to Falskaar you catch a boat back, kinda like the Isle Of Wight Ferry, or maybe Holyhead to Dublin, mayhap Loch Lomond or maybe even the Woolwich Ferry
There are some bugs, despite the author's claims, but in my experience very few and those that there are, are very minor.