If the projector is close to the bottom of the case, then you would typically be at around 100 microns XY.
In that case, 8 seconds could be a bit short. The recommended resin exposure chart at:
http://www.kudo3d.com/recommended-printing-parameters-exposure-time-lifting-height-lifting-speed/
indicates 11.7 microns for 100 microns XYZ. When you go down below that, a rough rule of thumb is a 25% exposure reduction for a 50% layer reduction. That would be around 8.77 seconds, but I find a lot of times it may actually not be any different.
And your reasoning on the holes, since they’re oriented towards the fixed end of the vat, matches my experience. Reducing the lift height down to 10mm/min or 15mm/min should help reduce tearing.
Bulges are still a mystery… when printing large flat walled parts, I encountered tearing and experimented with different wall thicknesses, but never encountered bulging, so other than generic guesses about added pigment, I don’t have anything specific to share…