Could Flash (Super Hero - Barry Allen) Be immortal ?

There are lots of intense in the comics that flash vibrates so fast and matches the frequency of alternate universes and becomes coherent with them, he even could travel between these alternate universes. There is even a comic book issue where flash(The red one) travels in time to the past or even his arch nemesis reverse flash (The yellow one).

So my question is, if flash could time travel and heals faster with high metabolic rate, could he become immortal ? until he is killed. ?? (Even then the reverse flash could go back in time and save the flash - without flash, professor zoom has no one to play with). With his healing abilities could he be forever young and immortal ??

Another question arises, we know vampires are fast, is that one of the reasons why they are immortal until they are killed ?? (Well there are thousand ways to kill a vampire). Are vampires just blood thirsty Flash ??

Superman (The alien) - The fourth Dimensional being ??

So, I was very much intrigued by the concept of 4th dimension and the infinite dimensions. humans are a 3 dimensional beings who can view things only in 2 dimension. animals on the other hand like the reptiles and such are 2 dimensional beings who could see things mostly in 1 dimension. What it means is that animals could see things straight or linear, that is why animals cant see the 3 dimensional shapes and such, except for some monkey we experiment on.
That being said, if a being is 4 dimensional then it could see things in 3 dimension and could defy the rules of physics that humans are capable of, I think this maybe the reason that superman could fly, xray vision and even travel through time and does things that are impossible by a human by himself. Superman could even travel through time.
There is a villain in superman comics named "Mxyzptlk", now its a fifth dimensional being, this can see and do things in a 4 dimension. This makes this being to do magical things, that even amazing superman and which are utterly impossible for superman to do.
Now the questions is Human evolved from reptiles into monkeys and then into an intelligent being.If we keep evolving will we become 4th dimensional being ?? maybe not now but maybe in a million years (if we dont destroy human race by any means).
Another question is what if the aliens are 5th dimensional beings and travels in the 4th dimension which is the time thus making it impossible for humans to see them ? but they are just around us (around the solar system and not literally around our living rooms).

So we all are gonna be as powerful as superman after a million years when we evolve. We could just start analyzing about other superheros and see which dimension they are from.