Darkseid pimp-slapping Superman was recent in that the comic JUST came out. It shows what a current writer thinks of Darkseid compared to Superman. Where it fits chronologically is irrelevent since Darkseid hasn't been powered down and Superman is on the same level of strength now as he was at the time, only marginally stronger. You can see this from his fight with Orion in the same story.
Darkseid suckered Doomsday, which left him downed and not moving. Darkseid thought he was dead and left. Then Doomsday suckered Darkseid and made sure he finished the job without giving DS a chance to recover. They bothy suckered each other.
As for Black Mary, if she's more powerful than WW3 Black Adam as some people say then it's a decent durability feat that he just stomps the ground and says he's more powerful after taking a blast from her.
And judging by what Darkseid said, it appears he created Eclipso period. He didn't "help" create Eclipso. That makes him by definition > Eclipso unless there were some extenuating circumstances. It's a ridiculous retcon though. Eclipso is supposed to the the former Wrath of God, not a creation of Darkseid.