I had some under extruding on "roofs" issues but when I calibrated the extruder, the 10x10x10 perfect blocks became ~ 10.5x10.5x10.5mm. what should I change now? More layers on top and less extruding?
Block width is not the way to calibrate extrusion. You could calibrate on single walled objects taking an average as described in slic3r manuals. Or print a 100% solid block, then you soon see if you overextrude as filament gets higher and higher making problems if you are too high. That would give the correct amount but under free conditions it might be thicker as you want as you do not print a rectangular string.
On sparse infill or small layer height you need more top layer to make it look good.