I've owned a couple of OK's and their hulls aren't the thickest but they aren't the thinnest either and one reason they don't weigh as much as a lot of kayaks that are similar. That said, they are tough durable kayaks and have stood up to the test of time and have a very good reputation!
Ocean kayaks where pretty much one of the first and everyone else came along after.
I hate the ratchet straps, and you are asking for trouble using them on a kayak. Those straps are designed to ratchet down tight or they tend to slip, especially on a plastic hull, and that is why I wouldn't use them on any kayak.
These are the type that should be used. Just snug them down and you won't have a problem.