If 3/4" low means below square, that is way off, I would try setting it high, by .5" and try walking it down. Maybe someone else will comment on spine, I son't know those arrows, but assuming the spine is fine, start high, look at everything before you lower the nock point: get it centered, check for fletch clearance. Finally lower yur nock point until just a touch of high is left, bullet holes aren't necesary, or desireable. Stable arrow flight is what yo are after. Also look at your tear from a different distance, with that much nock low, are you sure you ae really clean at other distances?