The first leg out of NZ can be rough and you must time well in between the systems. Boats can get bashed on this stretch, avoid being one of them.
Onwards from Polynesia, the take off is easy and then you will be going more and more into southern wx with lows to the S of your track and associated fronts, shifts and swells.
Many boats enter way up high into the channels and continue inshore before rounding the cape. There are places to anchor
before the cape so that with a good forecast
the rounding is not difficult in the right season.
Get good anchoring gear
as it can blow down there very hard and anchoring
can be a combination of anchor/shore line techniques, etc.. Also, many anchorages
are deep. Good, and plenty of, anchorage gear