Hello. Your first question regarding iPhone and eMail have been on my mind... In a Nemeth transcription, these are literary words--I would not consider the letters to be abbreviations because they are each part of the word. However, retaining the italics for the i and the e makes for a messy transcription in any code. I am wondering what the Literary experts would say about ignoring the italics for the i and the e. By stating on your Transcriber's Notes page that these letters are italicized in the print copy, you will be able to braille these two words without the emphasis.
Your second question regarding book level: This is really a Braille Formats question but it is my understanding that when a level is indicated by graphics or colors, you are not to add a word (such as "Grade" or "Level") but simply insert a colon and then the Arabic numeral as you have done in your first example. This is according to Braille Formats (1997) Rule 2, Sec.2c3b.