When I show dogs, I wear shapewear. Always!
#1. if it is good & form-fitting, it should not make you hot & sweaty.
#2. Put it on underneath your pantyhose (if you wear it)
#3. high-waisted panty styles tend to "roll" down the waist if you bend over. I find if they don't go all the way up (just under the boobs), or have "boning" (plastic molds to keep it from rolling over) then it won't stay.
Not sure how "curvy" you are, but the best shapewear I found will go down mid-thigh (to prevent rubbing) & high on the belly w/boning. Depending on the outfit & shapewear pieces, I have been known to layer them!
Good luck, try them on & MOVE around, make sure that you can squat down, bend over, dance a bit, without worrying whether it will slip out of place. Nothing worse than wearing tight shapewear that rolls into a breath-defying donut around your waist!
T.