In Consonants^x, Pronouns^x

From The Elements of Style:Form the possessive singular of nouns by adding 's. Follow this rule whatever the final consonant. Thus write, Charles's friend Burns's poems the witch's malice Exceptions are the possessives of ancient proper names ending in -es and -is, the possessive...

It's not regional (except insofar as it seems to me to be more AmE than BrE) and not sloppy, in my opinion -- unless you want to say also that British speakers who say "choon" for "tune" are sloppy. It is "glide absorption", and it is the sine qua non of authentic American...

I think the best way to handle it on a resume is not to say I. Under education just put MBA university of.... Rarely have I heard of the pronoun I being used on a resume. So leave it out. In general writing a would be correct as m is a consonant sound.