1) Monero is still based on mixing. There is still taint there since there are traces of history. This is not a real step forward like zerocoin (or zerocash) which fully erases all history.
In fact even Zerocash has timing and other related side-channel attacks, such as vulnerability to IP monitoring. If you know
when someone sent a transaction and you are doing IP monitoring you can likely identify the transaction, even if you can't see what is in the transaction.
If you limit yourself to passive analysis of the blockchain (and ignore timing on the blockchain) then Zerocash is opaque, but the tradeoff for that is much newer and dodgier crypto than Monero (plus the still-trusted setup; their proposal is to do multiparty, but if you aren't a participant, or weren't around to witness it, you are still trusting it). There was recently a serious break in one of the crypto tools used by Zerocash. If that had happened with a live coin in operation the entire coin could well (likely would have been) destroyed.
I don't know if Zerocash will be ready for prime time soon enough to succeed. I'll certainly hedge in it if a coin launches and doesn't get too much too wrong though.