[PARAPTOR]

A thorough PDI should include energizing/pressurizing all systems. Things like loose water connections should be obvious during the inspection. I suggest taking say the forum PDI list and customize it to you rig including discrepancies reported by others (internet, forums, etc)

As far as walkable roofs, there have been previous posts on this topic, Try searching the forum, If a recall from the posts, in general, if rig came with a ladder than it was meant to climb up upon the roof (not a decoration or added extra weight to balance the rig). Not equipped with a ladder roof not walk-able.

As stated previously best to call Keystone with VIN number. Always interesting conversations, just prepare yourself ahead a time