Maybe it's just me but whenever someone uses the word "kawaii" and they aren't Japanese, it screams "Weeaboo" to me. Yeh yeh I know it's derogatory but seriously that person is asking to be ridiculed.
"Moe" on the other hand seems to be a generalised word in the anime fandom these days. I won't go into the debate of what it actually means (we'll be here for years debating that) but anyone who watches more than just the mainstream shonen titles (Naruto, One Piece, Bleach - wait Bleach finished. OMG) knows what it is.
Let me give you a example:
"OMG. Your bento is so Kawaiii! Itadakimasu!"
See what I mean
. It just sounds totally wrong. Compare that to this:
"Oh wow. That was totally moe!"