New ceramic glass top oven: A few questions?

1) The manual says that the use of cast iron cookware is “not recommended”. It says not to use glass as it will scratch. It says porcelain-enamel cookeware “may” scratch the surface. All it says for cast-iron is not recommended. Do you use cast iron, does it scratch? My cast iron pans aren’t completely smooth.

2) Do you use the conditioner on the surface after you clean every time? Sometimes? Never?

3) Any other hints? Stories? Experiences?

This was a Christmas gift which is why I am completely clueless. I only found out I was getting it two days ago!