With the goblin shacks, I think the highlight is fine, but I think the original is also good. The one thing that I would dispute is your use of black lines. They are overpowering on some of your isometrics.. Try to use a darker/cooler shade. That way you can soften the effect but still have the divisions. Especially when you use lighter colors, an outline color that is relative is better than using pure black, in most circumstances anyways. Your texture work is great. I think you could probably put a few more details into the work such as windows, or perhaps a little more attention to light/shadow directions... not necessarily strong light/shadows.
Your other work is pretty cool. I think with my outline suggestion, you could definitely improve the works by leaps and bounds. Hope you try some of these ideas out!