yeah i know but just because it's a swamp doesn't mean you need 2 billion liana trees. Also, maybe make some liana palms and notice that there are 2 verieties of liana trees or whatever so can have more veriety, which seems needed.
Edit: Actually decent map, and the swamp looks fine to me. I don't know what I had against it. I guess out of everyone, the person I have the most disagreements with is my past self, though I may disagree with that in the future.
map markers are not supposed to appear in-game and probably never will. I think this map is good for a beginner, but try to make a more level, smooth map without the jagged edges (use the smooth tool) and use more veriety in the map. Use the "fill map randomly" tool to create a more varied, random objects and it isn't good to have to many liana trees