Yea, that drives me nuts in SketchUp, something with any thickness should not have edges from below show through....
I tried many things before posting, like turning off the framing layer but it didn't work. I just figured out that the insulation also creates edges inside the wall assembly, so with both of those layers off the lines do not come through the siding or drywall layers. In styles, I turn of profiles and all looks good, so that problem solved!
The only issue that remains is that I have two walls meeting that meet but the bottom plates are at different elevations, the siding texture does not line up. The bottom offset on both is lined up, it's just the texture starts from some other point on the assembly. Could it be changed or an option to have the texture start at the bottom or top of the assembly, so that could be a consistent point between walls that meet that might be different heights?