#1
I washed them and they didn't "crumple" as one reviewer mentioned.  However I really didn't know where to put them to dry.  I had an empty shelf on my shower caddy so I laid them there but they had to lay with the edges up.  This resulted in a slight impression on the tips which I figured might show through a T-shirt.  So I re-rinsed them, tried using a clothespin on the edge but was afraid it would leave a big mark.  Now I have them laying "t*ts up" on a towel (I don't have a sweater drying rack which would probably work fine). So, they are a little awkward when washing & drying.

#2
I think they cover up fine.  If you want absolutely no indication of female breast properties you just should buy some armored bra.  I wear lace bras and like knit tops.  Now that I'm in a more formal office environment I noticed that nobody's nipples ever show.  I can't stand those stiff molded bras.  Although these inserts look like those bra cups, they are very thin and flexible and don't add padding which I don't want.  I am completely unaware of having them in my bra and they are unnoticeable to the touch. They don't give me a weird shape and they don't make my bra too tight.

#3
I wish amazon gave better sizing information because some of the sizes have free shipping and some don't.  Luckily I guessed right (bought M for 34C), but being a small C cup and wearing lace bras, I might try Small for my next pair.  The Medium are the same size as the cup of my bra but if not positioned exactly, they peek out an edge. It appears that if you are an A cup you are out of luck.  Here's the size chart from the box:

S  = B/C
M  = C/D
L  = D/DD
XL = DD/DDD

#4:
That flowery thing in the background of the photo is a storage box.  It's like a miniature hatbox (or giant powder box), very sturdy, with a lid that slides up and off.  Unortunately for me, the lid fits so snugly that I have a hard time getting it off.  Oh well I didn't buy these for the box.