Hi Charlotte,
The NZ physio board won't return your application (and take $150) unless you miss any of the Mandatory documents (e.g. course certificate, passport etc). If you were just needing a little bit more evidence in the competencies they will just send you a letter asking for it (and wont charge you). For the competencies just use all your uni modules/placements, courseworks, dissertation, presentations etc to prove them. Did you do a 3 year course? If so, you will need to work in the UK for a year before applying. If it was 4 years then you will be fine, the 4 year course matches up to the NZ course well, which is what they want.
Hope that helps.