then there is not necessarily a significant difference in complexity between a creator+universe and a universe alone.
I'm not sure why you're not getting this. Perhaps putting your premises into formal logical terms will explain it better for you
. . .
P1: Our universe (x) is complex
P2: A creator (y) would have some kind of complexity
C: Our universe plus a creator would be more complex than our universe alone (x+y>x)
. . .
Let's try another version (remember these premises are your statments):
. . .
P1: Complexity requires a creator
P2: Creators are complex
C: All creators require a creator (infinite digression)
. . .
These conclusions follow from your premises. And it's not hard to see why adding a creator only makes the problem worse. It doesn't by any stretch of the imagination solve the problem of where our universe came from.