It may be fun to just run around capturing criminals, but at the end of the day SPBs need to pay the bills. Any player that doesn't think about their character's economic situation in realistic terms is being irresponsible. I don't think it's necesary to establish a secret identity, though, because after several decades society will adapt to include the new members. Comic books seem to have dozens of UN sponsored super groups, but there must be other options. With a little thought, one can take an educated guess as to what economic doors will open to SPBs.
This is an obvious extrapolation on the way the corporate world might interact with SPBs, especially corporations with the capability for SPB creation. This is taken into account by HU2 in the experiment and robotics OCCs; the player character has a sponsoring organization and a relationship with that organization. A company thats invests resources in creating a SPB will expect a character to repay that investment through service, and other companies would find many oppurtunities for super powered employees. SPBs with offensive and defensive abilities would make excellent security agents and body guards. Companies with darker interests may create and employ corporate spies, thieves, or assassins.