Envelope deformation is not a good way to do curved labels. As it distorts the letters. You need to use a "text along path" tool. You should also generally increase the spacing of letters at least a bit for curved labels. Often it's a good idea to use spacing to stretch the label out to indicate the extent of the feature.
Fancy, ornate fonts make for bad labels. Keep it simple and legible.
Rivers don't generally behave the way yours do. The basic rule of rivers is that for any point, there is one route that's most downhill. So rivers merge together. There are exceptions in special situations, but most are quite small compared to the overall river system (anabranches and river deltas) and those that aren't are very unusual, geologically short lived, and require special situations. Artificial rivers (canals, magic, etc) may break these rules, but they require a reason and ongoing maintenance so you should be aware of when you are doing this.
You seem to be trying to maintain a constant visual density across the map. This should be avoided. It makes for cluttered, hard to read, and unbelievable maps. The arrangement of interesting things in space is not usually uniform. Some areas have more stuff than others. You need to let the map have a background in order for the foreground to stand out. So moderate your use of textures and patterns, particularly if they aren't representing anything, avoid compressing all your colours into the mid tones, and accept that some areas need to be crowded while others need to be sparse in order for a map to look real.
Try to think about climate, wet climates give you forests, where it's not wet enough for forests, you get grassland or scrubland, and where it's not wet enough for that you get desert. Human activity can remove forests, but this tends to be unstable (For instance, Europe would slowly revert to being largely forest if not for human activity)
Wetlands are limited in how big they can be. Avoid really enormous swamps unless you have magic backing it up. They necessarily have to be flat and exactly aligned with the water table. They tend to be dense terrain so they don't need to be particularly large in order to be significant to the game/story.