Expect Don would be able to assist - very thorough. More known for yachts but expect he can do power vessels - suggest phone him.
www.admiralmarinesurveying.com/about.html

Paul Burgess is also excellent, also Michael Lapin
www.seabreeze.com.au/forums/Sailing/General/Sydney-Surveyors?page=1

Yes that is commonly done eg see below but it would certainly be best to ask and have this confirmed by the surveyor you select.

vesselcheck.com.au/boat-insurance-surveys/

Most insurers won't allow an insured value greater than the purchase price - if they do it won't be much more. Good insurers will acknowledge increased value in a boat - eg new mast - and allow the insured value to increase.

Note that most small craft surveyors don't include engine survey in their scope.