Yes ... they are called "Snap-Tight" strainers and you can replace them ... https://www.homedepot.com/p/Oatey-4-1-4-in-Snap-Tite-Square-Strainer-Rubbed-Bronze-46267/205855472
You sure can. There are dozens of them. Check it out here ... https://www.homedepot.com/p/Oatey-PVC-Shower-Drain-with-Round-Stainless-Steel-Strainer-423102/305248405
Yes, the grey shower drain is Sch.40 PVC.
Don't know why Oatey is so secretive about the installation instructions, but here is a video showing how it's done ... https://youtu.be/f7Gb2SFjmnc ... no to gasket or caulk ... yes to plumber's putty
Oatey does not have a product for that application. There are products available for catching hair but we do not have a specific recommendation.
It is gray in color but is still Sch.40 PVC - any of our PVC cements will work for this item.
Yes