Actually isn't this what Netflix wants - people connecting to their Open Connect Servers. I see no reason why they would block access.
Likewise they can just turn a blind eye to people accessing content from other countries. Netflix (hopefully) wants happy subscribers and has no reason to stop this.
That said I suspect the traffic through unblock-us will be a tiny fraction of their overall traffic so I doubt they really care one way or the other.
I would think so, or they would be talking out of both sides of their mouths. Pressing for ISPs to sign up with Open Connect while saying its "free" to do so yet denying access to non-ISPs such as VPN/DNS providers wouldnt make much sense and only further open up their strategy to even more scrutiny. Its Netflix themselves who are offering Open Connect under the guise of a "free lunch".