WearAllWomens Strappy Sleeveless Ladies Camisole Vest Bodysuit Leotard Top - 8-14

is it of good enough quality to use as part of a cosplay?

If I buy more than one, can I combine postage?

is the 8-10 and 12-14 size listed below the S, M sizes for child ages 8year to 10 years? or UK size 8-10 adult? please explain as not clear.

Any good for a 6ft guy