In Toad 9.5, Code Assist would move and highlight each parameter as you type the parameter for a store procedure or function but not in 9.7.2. The trend tends to be, the more the parameter, the less likely the Code Assist hints will move.
None. The Code Assist hints will still display but it will not highlight as you type. You will still be able to see what parameters come next.
Waiting for fix in a future release of Toad for Oracle.