The deep sutures should not be palpable, even in very thin patients, whatever the suture material.
The muscles are generally tightened up to the umbilicus with a conventional mini tuck.
In the appropriate patient, a Hybrid tummy tuck (TM) can tighten all the way up including above the belly button through a mini-tuck incision.
Liposuction is possible with either technique and should leave minimal scarring, no additional if the liposuction is done in the abdomen. Usually if flank liposuction is done at the same time, separate 1/8 inch incisions are made in the flank area.