You really didn't address my concern.I know about conservation of energy. Assuming that it holds at the cosmological level - which is not obvious, since energy is lost during redshift, so for it to hold we need to assign energy to spacetime curvature which is a subtle thing - a spatially flat universe can have total energy zero, with the temporal curvature absorbing negative energy. So no problem there, but still- this does not address the creation ex nihilo or what those words are supposed to mean.
And I didn't get to questions 3-... because the first one already bothered me enough to post my reply
And I didn't get to questions 3-... because the first one already bothered me enough to post my reply

The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition