Okay. I assume you're working in layers? I hope so, because you've got a few rivers extending into your sea, which I'm sure you don't want. I'd do a selection based on your landmass, then invert it so you're selecting everything that isn't land, then do a clear on the river layer (hit delete, basically). That should clean up your "strays."
You might try a very small Gaussian blur to smooth out your rivers. Alternatively you could alpha to selection your river layer, grow it slightly then feather it slightly, and fill the selection with black, this should give you a similar effect.
I wish I could help you with fonts, but I'm only just starting to get cool ones. One thing you could do is learn some calligraphy and hand-write and scan in your labels like that.
Having looked at your introductory post, I really like the "cleaned up" 2nd version of the map. So consider my repping you right now a compliment for that one too.
What blend mode are you using on the layer with the colors?