if the mech hanger is bent no amount of tinkering will achieve a perfect result, so check that first. I bent mine and yet it looked fine till I checked alignment.
next: release cable at the rear mech and check the chain drops into the smallest gear. adjust limit screw, tighten up cable then manually push mech to largest cog and adjust limit screw. then muck about for a min or two to get the indexing right.
If its still ghost shifting it could be a worn rear cassette or the cable outer could be too tight and when the suspension compresses it tightens the cable and causes your mech to shift.