John does not wish to write these other things but would like to come say the words to them. He is not saying that he would write them with something other than paper and ink.
John wants to visit his readers but he does not know with certainty that he would be able to visit them. Alternate transaltion: "I plan to come to you" or "I want to come to you"
"Speak face to face" here is an idiom, meaning "to speak in their presence." Alternate translation: "speak in your presence" or "speak to you in person" (See: [[rc://en/ta/man/jit/figs-idiom]])