Predominately. It's predominantly. The former is a verb. You don't make adverbs out of verbs; you make them out of adjectives.
I'm kind of meh about verbing nouns. Since I'm a fan of saving space in writing, I like being able to say "So-and-so hosts" instead of "So-and-so is the host." However, I can't get behind the recent trend of nouning verbs: "the ask," "the reveal," "a good get."
Entitled for titled. You are entitled to your opinion about that book, but the book is titled "(Insert Title Here)."
"Between you and I." We all learned in school that "Me and John went" is wrong; it's "John and I went." But some people got the message that not only should the "I" go last, but that it should always be "I," not "me." It's easy to figure out which one to use: Recast the sentence without the "John and." "I went to the store," so "John and I went to the store." "She invited me to the party," so "She invited John and me to the party."
Then again, you have folks who avoid the whole issue by using "myself": "John and myself went ... ." I don't know if they use "myself" because they don't know whether to use "I" or "me," or if they think it sounds classier.
Principal/principle. They can both be nouns (The principal of the school is a man of principles), but principal is mainly an adjective, and principle never is.
Edited to fix misplaced punctuation.