I was about to write that the obvious thing to do here is to hire a building consultant but you have tied your own hands behind your back by not wanting to use a one.
A building consultant or project manager would not only provide you with the professional expertise and experience but the best of them will have professional indemnity in case of anything going wrong.
Allowing the insurer to choose the builder and then expecting them to ‘police’ them is just giving up too much control for the sake of not wanting responsibility (for something you rightly recognise is not in your area of expertise). Tell the insurer you want them to cover the cost of a “project manager” too, if cost is an issue.
At the risk of being accused of playing favourites (again), your next step should be to click on the IBC ad at the top of the page and talk to Chris Mo’ane about what your options are and how much they will cost.
You have had a big win – getting the remedial work done properly should be your priority.
On the question of the waiver, I don’t think that’s particularly fair as more defects could be revealed when the remedial work is being done. But, once again, you really need someone in your corner who has been down this road hundreds of times before and knows what can and can’t be done. Click on the ad – it won’t cost you a cent.