Static material for a neck loop sucks. Well, neck loops suck in general. I used a loop of bungee for a while around my neck till I got tired of the abrasion. I still use the bungee but I poke one shoulder through. This allows you to wear the bungee further out on your one shoulder, actually on your cave suit, which is much more comfortable. A bungee also solves that weight problem if you are carrying a heavy pack on your half round. The bungee just stretches a little more putting the weight of the pack onto your harness. This setup isn't great for really long climbs where you know you are going to rest. I use a 1" webbing harness for that or change to my frog walker. I try not to rest too long while on rope. I think you should do your resting between pitches where you will be more comfortable and not occupying a bottle neck for longer than necessary. I find that having a chest harness that doesn't allow me to rest comfortably for long helps me maintain this mindset.
However, my body type is what I would consider average so I don't have a terrible tipping problem. I also have a healthy gluteal protuberance. Harnesses don't fall off my waist