1. I believe you can! Zelda games post-A Link to the Past all have a generally similar structure. You explore, complete dungeons, and the world opens up more as you get more equipment, similar to a metroidvania. They're pretty accessible and so is this game. The only difference is this game is procedurally generated, so it's different each playthrough.
2. As far as I can tell, they're not really based on biblical angels. They're all closer to Eldritch horrors. They're "angels" in the same sense the monsters in Evangelion are "angels." Most of their names are also humorous and silly (ie Catsiel is a giant cat with a TV for a head).