Will Tor work with an "openDNS" system?
Does openDNS open my (computer) to access and snooping by the openDNS application?
Tor is mostly DNS agnostic. Building connections to relays is based on IP, so except for the connections that you make over it there are no DNS lookups.
The connections you make over it should be done using socks5h or socks4a, which means that the DNS look-ups are done remotely (by the exit).
Alternatively tor can provide a "DNSPort" to perform basic DNS lookups over. It supports A, AAAA and PTR records, which covers most "desktop user" requirements.
as far as I'm concerned, openDNS is a separate program acting like a DNS server. Yes, any normal-working DNS server can be set up to work in conjuction/"with the help of" Tor. Use an appropriate app security system like AppArmor or SELinux to protect yourself from malware - Tor is just a networking layer of another kind, it's not all-in-one product. So your openDNS suspects has nothing to do with Tor itself