Solution 1 -- cheap pantyhose. Eventually the feet get runs, but they stay in place better than footless tights.
Solution 2 -- dry wetsuit, dry body. Damp wetsuit, damp body. I haven't tried the cream rinse method.
Solution 3 -- inch the suit on from the ankles... the knee pads... the crotch... then flip over the butt. By then the arms and torso are easy.
Solution 4 -- Henderson Hyperstretch 3 mil with a back zipper. It makes a big difference. No more thinking I'm going to pass out trying to get the suit off again. Front zippers are difficult to remove over the shoulders without help. Keep the Velcro neck closure fastened onto itself, or it will snag the fabric shell.
Solution 5 -- in Florida, I sometimes use a set of Cuddle Duds or Warm Essentials long underwear over a swimsuit. They work just fine to stay warm, prevent sunburn, and keep the jellyfish at bay. I've seen them in the winter at Sears, J.C. Penneys and Target, but any synthetic set should work. And no problem making a quick trip to the bathroom! They are very see-through, so I wear black to the beach.
Taking a set of feather-weight long underwear might be a good idea on a liveaboard. I've never tried them, but the idea of being in an air-conditioned cabin after several days of non-stop diving sounds chilly to me. Plus, you can't control the weather at sea or during any shore visits.
Have a wonderful time!