I agree. I always start with the reasons and motivation for the dungeon before I get into drawing the dungeon. I need the context to be able to make a proper dungeon. It needs to have a reason for being made in the first place, a reason for surviving since it was built, and a reason for the things and monsters within. I always try to imagine why the original builder would make things this way.

I would probably do the coastline differently. That blue color doesn't look right when it ends up on the top of the cliffs like that. Maybe a different color, or maybe simply drop it completely. If you keep the "cliff mountains" on the same sheet as the landmass, you could use a glow effect for the coastline that would then trace the actual outside of the combined shape. Another option is to draw the coastline manually as a separate entity, and either skip it at the cliffs, or draw it at their base.

The orange line is the roof ridge for that style (It looks better when you zoom in much further). The reason it sometimes seem to disappear when you zoom out is that it simply becomes to narrow. Your screen only have a finite amount of pixels, and when something gets thinner than a single pixel, a decision will be made if that pixel should be displayed or not. Being less than a pixel, if you use a pixel to display it, you take away space from something else, so showing everything is simply not a technical possibility.

The same is the case for exports. A sufficient high res export may have more than one pixel available for each ridge, eliminating the problem, but generally, every export will have it's limits, just how images work.

The reason you can't simply change the fill is because they are symbols. Changing the properties of a symbol won't change the entities it is made up from. (May feel weird for a simple symbol like this that is just a single entity, but symbols are often made up of many different entities with different purposes, so just changing them all doesn't make sense). Symbols needs to be exploded before you can change the properties.

The Dundjinni Archives also have some Sci-Fi stuff in them