LYANERWomen's Warp V Neck Ruffle Short Sleeve A Line Swing Flared Cocktail Party Midi Dress

Does the sleeves at least cover half of the upper arm? I really don't like showing my arms.

I am 5'3" and weigh about 150 I'm a little pudgy in the tummy bc of having kids but my chest is small should I size down and wear tummy tuck undies?

What sizes are considered as US 12 ?

I wear 38 dd or 40 dd I'm like 5'3 or 5'2 I weight like 179 or 180 or so what size should I go with I usually get xl what should I go with ?