GLC, I am not an expert in the swimming, but about the "snot".
Took me a while. Mostly it is HOW you breathe out and you do need to also forcefully breathe out your nose. That helps. I tried the nose plug and it TOTALLY made me feel like I COULD NOT breathe at all. I found I got used to the pool, but first time in OW --salt water that is--my nose burned and burned. So I think you will get used to it. But try the nose plug and good luck w/ that!
My worst part was water in my ears. So I use ear plugs...thank goodness for those!
Glad you are swimming. Maybe I'll start back soon. Oh yeah, that is my "new years GOAL"--to start swimming again!