:)In my opinion, that is the whole point. In very much the same way as Michael Angel felt he had to paint God as a powerful and strong middle age man mparting life to Adam, in his Creation of Adam, in the Sistine Chapel, for he could not in any way even attempt to depict God despite all his artistic talent ALL those who had tried to describe God in writing (whether Saints or else) have stumbled upon the impossibility to describe God'sobvious magnificence with words or in any other way.
The "Alpha / Omega" sentence has always been used -wrongly, I believe- to express an idea of something infinite. That is the idea St. John is transmiting in his Book of Revelation.
But, as you say quite rightly, it cannot really be applied to God. We should never - I think - forget that God is the Creator of everything. The Universe and whatever it may contain.
Now then, if the Universe we know - and we still ignore whether there are other Universes - is so immeasurable , with billions of galaxies, each one with billion of stars separated each other by bilions of light-years - and we believe it has been created by God, it necessarily follows that the Creator must be well over and above his Creation, to the extent that for God there is no time (past, present and future are THE SAME THING), nor space or distance. God is everywhere AT THE SAME TIME, has always been and will always be.
When we die, we shall all probably have a glimpse of God's Glory and those who deserve it will have the privilege of sharing a bit of that Glory -whatever it is like - forever. Whereas, those who must be punished, will not have that privilege forever, too.
This is what I believe could describe Heaven and Hell.
But using the concept of time in the Earthly meaning, in a few more years maximum, I shall know for sure as well as whether I deserve to be forever glorified or doomed. I'm hoping on God's mercy to go "marching in, with the saints"... :):)