Wow, thanks for this post. Here i was thinking metamask was awesome. That kinda pisses me off really, especially since a lot of dAPPs rely on metamask and don't really make it easy to use other options.
Even if you use metamask as a "quick" wallet, This means that they can trace any transactions to or from that first public key... God damn wish i knew that, would have used a second key immediately.
I wish MEW would make an extension that integrates with dAPPS like metamask that you could use a hardware wallet with...