Have you noticed any difference apart from no start up noise?
Difficult to say, however at higher rpm, it feels like she's pulling a little stronger
Will they fix it free if my car is out of new car waranty?
If not too far out of warranty then they should fix it as it's a recognised fault. Advise them of the TSB number when you take it in.
Do you know what damage I will do if I leave it?
No idea anyone else know what damage leaving it alone may cause, maybe the actuator pin breaks therefore causing damage further in???
Is the "fix" the one in the TSB?
Yes