Conversion

[theVOID]

Without evidence to discern between your assumption and any other you have failed to meet the most basic requirements of a truth statement.

So then, "No proposition can be held as true unless it can be verifed either by empirical observations or logical tautology." Is that it?

No, not OR logical tautology(keep in mind this not need be the case for less significant claims), Evidence and Logical tautology. But for the most part i regard the human logic as rather meaningless without evidence when you get to the big questions. Quantum superposition and tunneling are fine examples where out predefined logical process is worthless. When you get to the first million trillionths of a second of the universe and everything is in the same state (unified field) and our logic and laws are worthless completely, so to make a statement about certain aspects of reality you need far more than just logical models.

Even if your TAG was logically flawless (which it is not) ...

Feel free to present its logical flaws. Let's see if you are correct.

Others on this forum have already done so.

The idea that the universe was the product of two gay hippos having anal sex ...

I think you have grossly misunderstood the TAG, for it is not a cosmological model.

No, it was a general example about statements of the unknown. Even the most stupid sounding thing you could imagine is equally valid an explanation when there is absolutely no evidence to use to distinguish one assumption from another.