3. What about DNSSEC?  Does this eliminate the need for DNSSEC?

No. DNSCrypt and DNSSEC are complementary.  DNSSEC does a number of things.  First, it provides authentication. (Is the DNS record I'm getting a response for coming from the owner of the domain name I'm asking about or has it been tampered with?)  Second, DNSSEC provides a chain of trust to help establish confidence that the answers you're getting are verifiable.  But unfortunately, DNSSEC doesn't actually provide encryption for DNS records, even those signed by DNSSEC.  Even if everyone in the word used DNSSEC, the need to encrypt all DNS traffic would not go away. Moreover, DNSSEC today represents a near-zero percentage of overall domain names and an increasingly smaller percentage of DNS records each day as the Internet grows.  

That said, DNSSEC and DNSCrypt can work perfectly together.  They aren't conflicting in any way.  Think of DNSCrypt as a wrapper around all DNS traffic and DNSSEC as a way of signing and providing validation for a subset of those records.  There are benefits to DNSSEC that DNSCrypt isn't trying to address, in fact, we hope DNSSEC adoption grows so that people can have more confidence in the entire DNS infrastructure, not just the link between our customers and OpenDNS.

стоило сначало на сайт заглянуть