For the newer versions of RightScale (V5 and above) connecting to ssh port 22 is not a requirement. So you don't need to add incoming rules to the firewall. However the RightScale software will make a connection back to their application using a few different ports. So if you have a restricted outbound rule set; you will need to add a rule for that. Here's the set of ports they use for communication:
These are not only operation control ports, but also ones for software updates.