The best thing about metal, is there is always something out there for someone. Things have splintered or been subcatagorized, but most can generally be lumped into certain subsections. There is Traditional heavy metal, (normal metal like from the 80's), Death Metal (growling vocals, double bass drums), Progressive Metal (complex song structures,mostly clean vocals), Black Metal (mostly satanic themed bands), Thrash (Slayer/Testament/Anthrax era sound) and Power (sometimes Fantasy themed, clean vocals, Helloween is a good example). There is a lot of cross pollination of genre's nowadays, which can be a good thing. My suggestion, is just listen to what you like on your radio stream. If you like a band and find links to other bands that might lead you deeper down the hole. For someone new to metal, I wouldn't recommend a KSE fan to go check out Emperor or something. It's totally different themes, music and style. It's a big step to jump from one to the other. You may like Emperor, but you need some build up to get used to the vocal styles and song structure changes.
I liked KSE. I still like some of the Howard era stuff. They had good songs.
I grew up in a strict Christian household too. Metal was a no-no, but that's what drew me to it (DnD also to a lesser extent). We've all heard that it's a pathway straight to hell, and that's what provoked me to see what the hubbub was all about. Metal has this stigmata from the 80's and the Christian religion that basically ingrained it into everyone's brain that it's "evil". I've been a metal fan for at least 25 years or more. I've yet to sacrifice an animal to satan, or kill puppies or anything of the sort and it's rather foolish that people believe that. It's about the same argument that video games create mass murderers. Metal is mostly about angst and frustrations. War, religious, political, whatever you're angry about, there is a song somewhere. It's also very positive. It can help you deal with bad situations and reassure you. The best part, is it isn't forced down your throat on the radio. No one tells you who to like on tv. You're free to explore and like who you ever makes your head bang.