looking at an 8’6" board which has a traditional (teardrop) nose concave found on longboard nose riders.
Wondering if nose concave on this short of a board could have a negative affect?
Nope. I put a big nose concave in a blunt nose 5’0" with low nose rocker and it is super fun.
http://www.swaylocks.com/forums/2015-bc-thread-my-version-blendingcurvescom-nug-b-50-x-215
And No. but that also depends on whether or not it is a SUNSET OR Waimea Gun.