"Astronomically small" is an understatement which conveys no understanding except an understanding of how blithely "but it is greater than zero" is subsequently stated.1/infinity does not equal zero. Rather, zero is the limit of x as x approaches infinity. But that limit can never be reached, because x can never reach infinity.
Therefore, 1/infinity cannot be equal to 0, but can be approximated to 0 for some practical purposes. The proof is 1/infinity, which is essentially a division of 1 into infinitely many parts. That infinity of parts, when summed, must equal 1, not 0. You can't make the 1 simply disappear by dividing it into any number of parts. Division is not subtraction. 1/infinity is not 1-1.
http://www.mathsisfun.com/calculus/limits-infinity.html
Jabba's original argument was that his conditional perspective is so immensely unlikely under strict materialism as to rule out strict materialism as the sole accounting for his conditional perspective. I actually agree with this part, with the caveat that it is very unlikely that any of us understand all the metaphysical implications of strict materialism.
I don't know what Jabba is heading for now. I don't agree with the immortal soul business, which I consider an unnecessary violation of Occam's Razor.
At any rate, Jabba-as-an-immortal-soul does not account for Jabba's conditional perspective either. How many possible souls are there? Infinity? Well, those odds don't look good for any particular one graduating from the ranks of the merely hypothetically possible.
In sum, I don't think either strict materialism or the immortal soul hypothesis comes anywhere near accounting for Jabba's conditional perspective.