(We really need to rope some other people into this thread, because it's actually a very beautiful and clean vector map you're producing here )

I think you've hit it pretty perfectly on the head with the smaller mountains ... it suddenly feels much bigger than before. A thing to consider is that mountains tend to form in lines (ranges) where the earth's crust buckles at tectonic boundaries. Now, for the kind of representation you have (basically: "here be mountainous and rough terrain"), you don't need to bother with indicating ranges (IMO) ... but you should think about what happens when those ranges hit the sea. The mountains don't end at the sea - they turn into islands, seamounts, underwater ridges and, often, accompanying marine trenches. I would expect at least the southern mountains to continue a bit further to the sides (east and west) with a few small islands or crags.