sidingmaster

Bad cut right there. This will pop out for sure. I have installed siding for 20 years and see this all the time. Improper installation. Improper installation typically means no warranty.

The reason that the 2 inch J-channel is needed is because this is a long length 29 foot panel. As far as a drainage plane goes, I believe you need an airspace behind insulated siding because there is no air gap behind insulated siding unlike hollow back vinyl siding. This can cause water to pool and soak into the substrate in certain situations. Manufactures have came out with drainage mats for insulated siding because of this. Codes are changing in the future to deal with Moisture behind siding. I would never install any type of siding including hollow back vinyl without an air gap to drain and dry out the moisture.