Most VTTs create their own grid overlay, so having one on a map that's intended for VTT use is unnecessary, and in some cases annoying. I'm pretty sure there's a way to modify an existing path so that the line goes through a vertex with a curve instead of a corner, but I don't remember off the top of my head how to do it. I think it would be a good thing to apply to the path—the straight lines are unnatural.

Give some thought about how the fight will play out considering the chokepoint. You may want to provide more territory outside of the building—if I were using this map, my players would almost certainly want more room to move about outside.