The heaven thing is poor. In the first episode it was an interesting concept. Now it's the same thing every week with very little new information revealed. "Yes clueless onlooker you are indeed in Heaven! Ho ho ho, you so silly to act shocked and confused, don't you know this is a perfectly normal thing?" It just feels like something they've thrown in to show the series is building up to something big at the end with very little actual substance or thought to it. No, this is not some mystery to figure out, it's just poor writing.
In my opinion it would've been more powerful to just spring all those people on you in the last episode out of nowhere rather than the "hehe guess where the finale's gonna be guys!!! BUILD UP THE HYPE TRAIN!" episode enders.