The orange layer between the 80 mm Anticon blanket and the top of the rafters is the foil backing on the insulation. Where it is taken up and over the roofing battens it looks like a separate material, but it's just the foil backing. The layer between the plasterboard and the rafter end is 15 mm plywood. Similarly, under the boxed eaves there are actually three layers of material - 4.5 mm fibre cement to protect the plasterboard, then the 16 mm plasterboard, then a layer of 15 mm plywood. As you say, the layer of 15 mm plywood is un-labelled, but is identified in the BAL-FZ diagram on p.

"Common studs" can be crippled (straightened) with a sawcut and cleats as per Fig. 6.2 of AS 1684.2. Crippling is limited to 20% of the studs in single or upper-storey loadbearing walls, ie. the "common studs". Studs supporting a concentration of load are a special case. These must not be crippled. Calculation of the input to determine sizes of studs supporting a concentration of load is explained in clause 6.3.2.2 and illustrated in Fig. 6.13.

Preservative-treated round poles achieve a high level of protection. The easily treatable sapwood provides a continuous band of treated wood around the heartwood core, heartwood being less easy to fully penetrate with preservative. There is some evidence to suggest that concrete encasement retains moisture at the concrete/timber interface and thus creates an increased risk of decay. However, it is not considered a significant risk in the case of CCA-treated softwood.

The cladding installation details on the WoodSolutions website are intended to be generic, ie. applicable to all types of timber cladding.  By clicking on the "Installation" tab you will find details of recommended fixings, but they are not specific to American red oak. We are not qualified to advise you on warranty issues and are not sure what warranty your supplier has offered, if any. It would seem that if the supplier has referred you to the WoodSolutions installation guide then they have adopted that as their product guide.