Awesome first try at the style, Morgan. First your questions - the color & brightness work well, especially the second version. Only trouble is you're going to have the dickens of a time putting labels in and getting them legible without taking over the show. The lighter texturing of the second one will help with that, plus as you say there's plenty of variation already; too much starts to muddy the look.

As far as any paper texture at all - think about what you've got. This is a near-photographic satellite view. THere's even sun-glint on rough water, or maybe debris in the water in places. How did a cartographer put it on a surface? Is it painted? If so, perhaps it's on a dead-flat substrate. Just what you decide for a margin is going to make the medium more obvious, so you can tell a bit of story just with how it's presented. If it's a period piece, no way is it mass produced. So your margin might indicate the wall it's painted on, or the sheet of metal, or whatnot.

Now since I've got to keep this RP badge shiny, I have thoughts about your water. It's not quite a satellite view, since I assume you've exaggerated width of some rivers so they'll show. Some can be estuaries and actually BE kilometers across, but not all, not plausibly. And I almost have to read the majority of the water as being right at sea level -- the little neck of an isthmus NW of center doesn't have shading or terrain to make the eastern body of water appear any higher altitude than the western side. The fairly regular widths and particularly narrow width of one of those skinny watercourses sure look like you're saying "rivers connecting a series of lakes" but visually I'm not buying it. If you really do want them all sea-level, you could "say so" better by varying their width more.

One place just SE of center you've got a decent-sized river implausibly splitting. Again - I'd buy that as an estuary where the island is bounded by drowned valleys, only the skinniness of them says "river". Rivers pick one best course downhill, and only under rare circumstances would you find a split of that size. And speaking of "one way only", you ought to break apart the triple-join of headwaters atop the mountain a tiny bit E of dead-center. A mountaintop lake could source a river, but only one. If there were ever two outlets at the same altitude, one would quickly "win out" over the other.

The textures and topography are all very nicely done. The scale sends a bit of a mixed message though. The trees in that NW basin "say" it's maybe a mile across, while the mountains ringing it declare no, it's a hundred or more miles across. THe volcano's awesome. The lava pattern says to me "cracks" rather than "flows", but that's nitpicking. It expresses very well that the place is a glowing window into the netherworld and I don't want to get too close.

What do you figure on using it for? That'll slant just how you want to border and label it.

My time's been so limited I'm going ahead and bestowing a smidgen of rep - it's worth that, already. Good work - dare you to make it better!