You've gotten good answers, and hopefully they help. If you are struggling with settings and whatnot, I usually find a good YouTube review or two to be far more helpful when it comes to actually figuring out mod settings and etc. It's more helpful (to me) than a thousand user manuals.
I'm glad you are asking. Some materials have to be used in TC mode, such as Titanium and Nickle otherwise bad byproducts can enter your vape as they overheat. Kanthal can only be used in wattage mode (for the most part a few mods claim to be able to do TC with it) and SS can be used in wattage or TC mode. I usually use SS because I can get a feel for my build in wattage mode and how it vapes. I usually use whatever works in wattage mode as my ramp up wattage in TC, and as far as temperature ceilings, anything under 420 F is considered fairly safe, assuming you have decent TC. I use a ceiling much lower than that, but I like a cool vape and am a MTL vaper.
Lots of experimenting and fun to be had, etc.
Anna