hi just lace,
yup..nt sure about doing the vows again at the office, but then, u still have to go there to collect your cert before your solemnisation outside.
Own vows do not need to be approved by any authority ba. Juz let your JP knoe tat u are using your own vows, and make sure that he/she is okie wif it...
im writing my own vows oso, and mi JP is fine wif it...so i dun c a big issue there...=]