One-Page Checkout [Support Thread]

[lat9]

Another question, would it be possible to disable/remove the need for entering a telephone number when the customer checkout using the one page checkout? Either remove the field completely or at least make it non-mandatory.

Just like a regular customer creating their address record. Go to the admin's Configuration :: Minimum Values :: Telephone Number and set the value to 0. That removes the requirement for a telephone number entry; it doesn't remove the field from the customer's display.