It is not a sunblock screen - although there are options at the store for that.
I believe it is standard and if you are replacing a 35 -36 inch wide screen, it should fit. I didn't consider the spline size and did not have any fitting problems.
Yes, just ensure to use the correct size mesh.
You are given so much material to be used for one screen cover. This easily fit my screen door with no problem.
Enough to go around a standard screen door.
VERY GOOD PRODUCT TO WORK WITH
paid $9.38 plus tax in the store
No, the material is not made for heat. I would be afraid that it might reach its melting point and become a sticky mess. Try looking up hardware cloth, but you want to make sure you don't have too fine a mesh as your HVAC system needs to 'breathe' properly and any mesh will restrict the airflow.
As stated in the online details, and on the package, the spline diameter, 0.160 (5/32).