Dying star?

[Serapy]

Rinoa waving her finger at the Star in the beginning and the ending definitely wasn't a coincidence. At the ending, she waves her finger at the star to symbolise the moment they've met from the beginning.

The link there is Rinoa's habit. Not the star. Nor is it a 'symbol', it's a reference.

You're admitting that this 'reference' is not meaningless? Finally!

The moon looks about the same as the one in the present era. Yet, the star looks red. That star being red takes place outside of her castle.

And again, this is absolutely no problem to an 'atmospheric discoloration' explanation.

This proves that the star is dynamic based on time periods and thus Ultimecia's time period is about millions of years later, hence the star dying.

I don't know why you would want to argue against this. Because if it's actually millions of years later, it would be utterly impossible for Rinoa to reach to Ultimecia's time period.

Visuals are always meaningful if they keep showing up in certain areas of the game, apparently.

This visual does not 'keep showing up' so, by even by that logic, it's meaningless.
Not that your argument is evidence, of course.

You didn't provide evidence that it's meaningless, either.