Go back out with foremost of Romeos for a start! (7)
I believe the answer is:
regress
'go back' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
(Other definitions for regress that I've seen before include "Go back to earlier state, perhaps of health" , "Go backwards, disimprove" , "Lapse" , "Go back to a lower level" , "Return to former life" .)