The second reason is one I'd like to ask your opinion about. Would wearing a rash guard help me put the wetsuit on?
A couple of suggestions:
1. What kind of lining does your wetsuit have? If velour, then putting on the wetsuit is easier if you and the suit are both wet (better), or both dry.
2. When I first started diving (late 1980's) and people were wearing wetsuits that lacked a lot of the stretch and velour linings that many of today's wetsuits have, people would sometimes wear pantyhose (on legs) and over-the-calf-hose (on arms) to help them don their wetsuits.
3. I have been watching a lot of free-diving videos lately. Some of those divers wear a two-piece skin-in suit (I think) with a built-in hood and a beavertail, and they use a spray bottle (of soapy water?) to wet both themselves and their wetsuits to aid donning.
Good Luck,
rx7diver