Horse poo, you don't need fancy drysuit undergarments. Like you I don't dive a dry suit much 4 or 5 dives in the fall/early winter and again in the spring. I use my regular thermal underware covered with lined sweat pants, a sweatshirt on top and thick wool socks. I dive this comfortably down to 45 deg, any colder than that and I am staying topside. It is most likely not ideal but for a few dives a year it's fine. I already own them and I am not cold, what more do I need? I doubt it has any real issues with my weighting, I dive 22-24 lbs with an AL 80. I agree learing to dive the suit is a challange but once you get the hang of it, it's like riding a bike, a dive or 2 and most of it comes back.