Very long vent about relationships

Background info: I'm from a culture that doesn't condone dating unless it's for marriage. 
Ok, so I've been dating this guy (let's call him BF) for almost a year and a half now, and I love him to pieces, but I know there can't be a future for us because he's not part of my religion and he has no intention of converting. Knowing this, I'm keeping my options open for more eligible guys (aka from my church), but I'd never be unfaithful to BF. I'm just befriending other guys. Nothing more. The rest of the guys I'm going to talk about are part of my religion. 
Guy 1: let's call him A. A goes to college with me and is perfect on paper. He's cute, smart, athletic, religious, family oriented, and is almost guaranteed to be a successful doctor one day. We hang out a few times a week, but it seems like our conversations don't stray far from school, sports, or church. He's a nice friend but I don't see a relationship evolving with him. He told me once that he doesn't want a relationship until we gets into medical school, and once he does there's no guarantee he'll even stay in the state. If a relationship did evolve however, I wouldn't fight it. 
Guy 2: let's call him M. I met M on a church trip to New York, and in the one night we were both there, we clicked instantly. We exchanged numbers and texted, talked on the phone, flirted a bit, and it was amazing. For about 2 weeks. Then he just stopped replying to my texts, and now I get a snapchat from him every few months. I don't know if I said something that scared him off or what, but I honestly miss this guy. He was very attractive, smart, sweet, funny, athletic, and we have so much in common. I could see a future with him the moment we met. But clearly that's not going to happen now 
Guy 3: let's call him K. K goes to my church and we teach Sunday school together.  He's one of the nicest people I've ever met hands down. He always goes out of his way to make sure everyone else is happy and healthy and safe. We both want to move to California and go to dental school there. I think I could have feelings for K, but I'm not really sure. It feels like one of those high school crushes, but I can't seem to shake this one off. I've had some feelings for him for a few months now (since we met) 
Guy 4: (last guy I promise) let's call him N. N is very cute and a bit of a flirt, which I really like since that's uncommon in my culture. I just met N a few weeks ago, and we really get along. However, he's 21 and not even in college yet, and I don't think I could be with someone that isn't career oriented at least a bit. I think once he starts school my feelings for him will change, but right now we have this innocent back and forth flirting going on, but I still feel bad about it considering I'm in a relationship! That and I don't want K to get the wrong idea about N since they're good friends. 
If you actually read all this, I promise I'm not crazy or a cheater, I'm just a really confused 20 year old girl!