Right now my "Additional DNSMasq options" is as follows:
1. can I specify OpenDns for the first and genuity for the second (i.e. 188.8.131.52)?
2. can I specify more than 2 IP addresses?
Yes and yes. DNSMasq allows as many -S (--server) options as you like. There is no issue using different DNS providers (in fact, it's a good idea).