The fixed word-final E that marks "long vowels" has the special name "silent E". (If it's not word-final, it won't appear at all. Thus "mating" has a silent E overridden by the -ing that follows it, and in order to spell a "short A" in the same context you need to divorce it from the following syllable by doubling the syllable-final consonant: "matting".)
But you can't use this as a basis for English spelling reform, because - to choose only the most obvious problem - English uses a lot more than 10 vowels.
So, when you write réad, am I supposed to understand /ɹi.æd/, a two-syllable word with a long E followed by a short A? When you write "had a", am I supposed to understand that both words are pronounced with identical vowels? When you write "lives", am I supposed to understand that this is a two-syllable word in which the first syllable contains a short I and the second contains a short E?
What problem are you trying to solve? How would you spell "put"?