The worldbuilding is very shoddy because too many authors worked on the canon over far too long a period. Even accounting for the "New Testament" sequel, it's retcons on top of retcons. The "Islam" spinoff at least managed to start with a clean slate, despite several callbacks to the prequels.

When I became a parent I thought about the whole "I am your creator, love me or I toss you in that lake of fire" thing, and it really hit home how fucked up it is. I'd dive head first into fire so my kids could be spared any pain, and this god psycho with his conditional love, is running around threatening eternal agony, while telling you he cares about you.

I believe "the satan" literally means the accuser.

I think there's kind of two concurrent perspectives: one of Satan being an evil being, trying to corrupt people away from truth, life and the worship of God; the other of Satan as an accuser and tester, bringing into view and actuality the evil that's in people's hearts/lives.

I believe the 'official' interpretation would be that there's elements of both, and the full truth about the satan is more nuanced/profound than we've yet understood.