All these event match if you read the sin war. There are gaps if you played D3 because the reaping isnt mentioned in here(D4) But the bridge is between the sin war and D4.
This is directly due to bad writing, there is a Prava plot with him, there could be any other angel or demon that would follow him, if he were a well-developed character with merits there would be infinite possibilities.
His premise was to escape the eternal conflict, they could work with that.
But they preferred to discard everything he did and sacrifice him in a poor way, in the best case scenario making him a demon in the future.
I came to the conclusion woke made him a character with none merits. The father of all humans, has no good quality… this is how bad he is written.
Inarius exiled Lilith because she slaughtered every single angel and demon, who allied with Inarius and Lilith earlier. And she did that when found out they are conspiring on killing all Nephalems. As they started truly fear their powers.
At a time Inarius still had feelings for her. So instead of outright killing her (which he could, as he was stupidly powerful at a time), he just exiled her to the Void.
No because lillith went haywire on the sin war… lol
And something just came to me that during the reaping malthael did a raid on pandemonium, maybe he freed inarius before going full rogue and leaving his position as wisdom in the council.
You are quoting the wiki 
read the trilogy, its far better than a quote.
She was right.
Inarius was right in nerfing nephalems instead of killing them.
They were atomic bombs without control.