The usual pronunciation of I (the pronoun or English letter) is the same as the word (eye). However, the pronoun I is sometimes "extended" as (aye), a long I with a very soft long E on the end,...
It depends on the person. Some say Ay-Tee-Ay-Tee because of other walkers, like the AT-ST, AT-PT and AT-AA. Others say At-At (@-@) because it's more efficient to use just two syllables rather than...