That's not logical reasoning, that's merely a fact derived inductively from everyday observations.
The point above actually has a physical law. It's called the First Law of Thermodynamics, and the Big Bang Theory is in stark violation of it.
Again, the first law of thermodynamics is a "law" which describes everyday experiences within our own universe at the present epoch. But Big Bangs are not everyday in-universe events.
The Universe will always be here. It has always been here. It cannot go away. It is indestructible and everlasting. The mystics understand this, and so does anyone who understands basics physics
That's just an unjustified assertion, and it doesn't really solve anything. Oh, and I'm sure that "the mystics" disagree on these things, as there's plenty who will tell you the universe was belched out of the belly of a giant porpoise. (If you ask them where the giant porpoise came from, they will get angry.)
How and why the universe started, and why we have this universe rather than any other, are two of the trickiest unsolved questions there are, but the Big Bang is the most sensible theory we have at the moment.