1. There is actually no requirement to turn rotors when replacing brake pads. That is only done if the are warped. Most OEM's now suggest only measuring the rotor thickness.
2. Yes, new pads can do this, especially ceramic pads. What I do is "set the pads". After installing new pads you need to take the car upto 20-30 mph on and do a few very hard stops. This will set the pad surface. It causes the pad form to the rotor and conditions the pads surface.
On my F350 truck I just did pads this last week. It is common on heavy trucks to get a brake groan about mid way through. This is often called, brake glazing. New pads and a few hard stops cure this noise.
In some cases people will use an angle grinder or orbital sander with light grit to "rough" up the rotor surface. This also removes rotor "glazing".
3. In some cases when your OEM says your pads should be Semi-Metalic, installing Ceramic is not a good idea. Ceramic pads are harder and give great pedal feel, but will ruin a set of rotors. On my 05 Wrangler with 35's, I installed Ceramic pads, after about 10k miles they started squealing, I inspected them to find they glazed the rotors worse than semi-metalics. So I switched back and didn't have issues afterwards.
4. I do understand that some OEM's supply Ceramics as stock pads. So be prepared to understand that if you have your factory rotors and new pads you need to "set" them properly. If at anytime some one installed a cheap set of rotors but you are using "oem" quality ceramic pads, the cheap rotors may not like that very much.