Script of Life: Do we author our own identities ?

You bet we do. On many -if not all-levels. If we talk on a more superficial plane, for instance by telling the same stories  over and over again about ourselves and how we came to be what we are now. Until those versions become truisms, something we believe in ourselves. Not because we truly came to be like that, but because repeatedly croaking out the same old refrain eventually creates its own fatal spin and becomes an entangled self-fulfilling prophecy. Which in final consequence is far from full-filling for the Self. Rather the opposite, really, as it first creates a void and a then a negative vortex by distancing the teller and the told from the authentic experience that once was.
The same dynamics happen to occur on deeper levels, when we continuously and willingly unconsciously chose to feed  existing patterns of an internal software that sorely longs for an overdue update and entire system restart. 
If we talk love, we may have to realize that we self-scribble the scripts of our relationships. We emanate energies in resonance with our internal wavelengths and thus call people, settings, situations into our lives.  We attracting our shadows, the complementary other. Bingo.
If we talk free will, it might be in place to recall that every single of our choices, unconscious, conscious, semi-conscious actively contributes to our thus self-fathered and mothered autobiographies, which might rather be called individual mythologies.
And hey, of course do we author even our own family systems. We so to say birthed them into being, so they might humbly serve as our objectively speaking perfectly-tuned (even if one might like to subjectively decline) incarnation frame. It´s somewhat of a new age cliché, but nonetheless another level of our authorship.
Thus, the only real choice is to assume 100 % Self-responsibility for what and all-ever one has written into one´s Script of Life
                                                          Easy to write, easy to read.
                                                          Hard to get. 

                                                           If you can´t beat it, eat it.