Usually the item was sold but they dont go back and update the listing as sold b/c it takes more time then just clicking the "close' button, BUT if you really want to try, send them a PM and ask if its still for sale.
Questions about the new Buying and Selling Classified questions - Page 20
Kinda.... use the advanced search function and then just type in the size. Will narrow down the search a lot but if you search for size 38 you'll get size 38 suits and 38 waist pants obviously.
Welcome to SF. I would suggest reading the entire B&S rules before postings as to not break any of the rules. You will notice about half way down: