Wouldnt they have Iceland though? That should help them getting around England.
Not really, given how underpopulated and under-resourced Iceland is.
IA: Sure. But England being in the way is an obstacle that they have to face in a way that a power that doesn't have it in the way doesn't.
Sian: Um, actually, it was a problem for the Dutch. I'd quote Kennedy here, but I think it might be just as useful to point to just point at the map.
I'm not saying they're going to invariably lose - far from it - but they're in a more awkward position for Atlantic exploration with England in the way than they would be without it.
Meanwhile, while they may have all those resources, they also have a pitiful population and not a whole lot of urbanization - this might change with a POD in the 1400s, but it isn't one of the most developed areas of Europe (not especially primitive, just that there isn't much drawing it away from rural-and-agricultural - even by Gustatus Adolphus's time 95% of the Swedish population is in the "peasantry" category, and trade revenue is "a fraction" of the United Provinces or England/Great Britain in the 17th century).
Not sure how much that would really change with the kingdoms united. It might not be quite as extreme, but it would still be far from ideal.
So I don't think we can say their situation is going to be better than England's on the strength of anything we see OTL economically.
Oh, sailing 'round Scotland just means choosing to face the absolutely ideal (dripping with sarcasm if you can't tell) sailing conditions of the North Atlantic instead of facing the English fleet. You -really- sure you prefer that?