Chall...I think a lot depends on where you live and what is meant by coastal crusing. Some of the bluewater boats I like a lot (med to heavy dispacement) would be quite poor choices for sailing here on the East Coast of the US where light winds prevail during sailing season. They would also be poor choices for those who enjoy tweaking things to go a bit faster or doing club races. If I were sailing the Chesapeake, I'd probably prefer a Beneteau to a Tayana. Of course there are also issues of living space, entertainment and how much more expensive a bluewater boat is than a similar sized coastal boat.
I like to think of coastal boats as sailing within 24 hours of a safe port and reachable with ease by coast guard rescue services in an emergency. The reality is that here...probably 90% + of all coastal boats never get 12 hours offshore let along 24.
I am not familiar with OZ sailing and weather forecasting or typical wind/sea conditions but I think most coastal boats over 30' are perfectly capable of handling 8-10 ft seas and 30 knot winds with a decent captain...but a sustained 2-3 day gale might have a few things shaking apart. So good weather reports/forcasting in your sailing area is also a consideration when thinking about a boat. The Sydney/Hobart tales I've read indicate that things can go rather quickly from benign to horrendous without much notice but perhaps that has changed with modern forecasting.
As to individual tales of things going badly wrong fairly close to shore...one thing I've noticed is that some VERY bluewater boats have had similar issues and I attribute the overwhelming majority of gear failures to poor maintenance regardless of the quality of the boat. There of course have been known production defects in some boats, but that is a different issue.
Anyway...hope this is helpful and I will be interested in others perspectives.
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