Looks like dude is stuck with being our Love God.
Well it's D&D Magic, so there's also rules about you probably can't/shouldn't mess with other clerics' magic as that starts weird divine conflicts. But You probably have a majority of the Arcane worshipers.
I certainly HOPE so! If not on it's one we could still make it one I guess.
Well it's D&D, so they may have to go to the respective planes of their alignment to be judged and given an appropriate afterlife. And that's before Gods want to actually get involved with specific super-heroic souls.
How do you mean? Even the OP gave the Death purview as also having power over the Underworld and Ghosts/Undead.