1) SDC rules are set by the operating carrier. Any segment operated by UA follows normal UA SDC rules regardless of plating carrier.
2) In general the late delivering carrier is responsible for rerouting you. They they may actually reroute you to CCC, unless they can reroute you to YYZ or FRA in time for your next flight. I suppose they could just reroute you to YYZ on AC, then even if you misconnect it would be AC's problem not UA's, but I think they're unlikely to do that unless you really piss the agent off or BBB is EWR.
3) Yes, you can get ORC.
RULE 24 FLIGHT DELAYS/CANCELLATIONS/AIRCRAFT CHANGES
E) Schedule Irregularity
2) Delay, Misconnection or Cancellation
a) When a Passenger’s ticket is affected because of a Schedule Irregularity caused by UA, UA will take the following measures:
(i) Transport the Passenger on its own flights, subject to availability, to the Destination, next Stopover point, or transfer point shown on its portion of the Ticket, without Stopover in the same class of service, at no additional cost to the Passenger ; or
(ii) At the Passenger’s request, provided that the tariff covering the original transportation permits routing via the carrier which will transport the Passenger, UA will re-accommodate the Passenger in the same class of service on the next available flight on another carrier, or combination of carriers, if the length of the delay to the Passenger’s destination exceeds two hours.