I completed a passport application form earlier this week, there is nowhere on the form to request a start date.
You can use the passport express option, which should take 10 working days provided there are no problems with the application or photographs. (I'm aware that there were delays with this service, as mentioned by some AAM posters).
There is an option on the form to enter the name you wish to have on the passport. The information guidelines on the form state:
"If the name by which you are now known differs from the version entered on your birth certificate or most recent passport, other than through civil marriage, civil partnership or adoption, you will be required to produce documentary evidence of the constant use of that name for at least 2 years"
The guidelines go on to give examples of the evidence required - bank statements, social welfare or tax documents, driving licence, medical card.
You can have your birth certificate name recorded on the passport too, on the observations page if you wish.