I think you raise a very good and necessary point in cautioning against taking our present perspectives too seriously. Time is definitely one of those slippery things that even now I suspect we hardly grasp, if at all. I find your comparison of time to changing states interesting as well, considering that “heat death” is, in a sense, the end of changing states altogether and thus, by extension, a kind of end of time. That’s definitely something I’ll have to think on more.