Hi snowtorious,
This is polyfoam and is less than 2" so it would be fine.
You can read more about foam encasement and edge support with innersprings in post #2 here.
No all the layers are good quality materials and as you can see in the guidelines here … there are no obvious weak links in the mattress.
There is more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you assess the “value” of a mattress purchase. Value is always relative to what else is available to you or that you are considering as a “finalist” and the criteria that are most important to you but if the mattress is a good match for you in terms of PPP then it uses good quality materials and the price seems very reasonable to me as well.
Phoenix