There could be hypothetical imperatives, but these are only hypothetically binding. This is usually dissatisfying for moral realists.
		
		
	 
Yeah, and in the absence of proof for the existence a God, God´s alleged imperatives are also in the category "hypothetical".
	
	
		
		
			Because the creator has total authority over his creation.
		
		
	 
Says who?
	
	
		
		
			His laws tell us how creation works best.
		
		
	 
How exactly am I morally obliged to help creation "work best"?
	
	
		
		
			When the laws are transgressed then creation breaks down and life is destroyed.
		
		
	 
Ok, I guess I am going to borrow from your previous argument ("Why does causing pain to others oblige me to stop causing pain to  others? What if I like causing pain to others? What if this is my goal?"): 
Why does destroying life oblige me to stop destryoing life? What if I like destroying life? What if this is my goal?"
	
	
		
		
			So they are categorically binding - you really are obliged to obey him because you owe him your very existence.
		
		
	 
Doesn´t follow.
 
	
	
		
		
			But they're also hypothetically binding - if you want to live and flourish in his world then you ought to obey him.
		
		
	 
If I want to live and flourish in this world I need to look at how the world works - no matter whether and by whom it has been created. 
	
	
		
		
			I'm not sure what you're asking here. Could you rephrase?
		
		
	 
Well, I´ll try:
For you (if I understand you correctly - but otherwise you whole line of reasoning doesn´t make any sense) the only way for there to be an "ought" is the command of a personal authority. (I do not agree with this authoritarean view on things anyway, but let´s just put this aside for a moment). And, of course, for such an authority-oriented person like you the most powerful entity is the greatest authority. If a God exists, God would be more powerful than anything in Its creation - so God would be the Highest Authority. However, in the absence of a God, you would have to go with the Highest Authority available in that reality: This authority would be the one to determine authoritative "oughts".
	
	
		
		
			God, by definition, is the supreme being, the creator and source of all other things. So the concept of a METAGOD doesn't really work.
		
		
	 
METAGOD, by definition, is the entity that created God. Thus, it´s defined as a Higher Authority than God. In the absence of a METAGOD God would only be a lesser authority. 
So much for defining entities into existence in order to establish a "either it exists or there can be no 'ought' or morality at all. If you can do it, I can do it. 
 
 
And then there will be next guy who postulates a SUPERMETAGOD. 
