Who am I talking to? - Distance and intimacy, formality and informality in vocabulary choices

Who would I probably say this to?
"I really liked your talk tonight."

A university professor who gave a lecture

Who would I probably say this to?
"If I may say so, I wholeheartedly enjoyed the discussion this evening."


Who would I probably say this to?
"You can't talk like that to me. I'm not taking any more of this from you, get out!"

A friend or romantic partner who made me very angry 

A professor who continually critiques my words in class

Who would I probably say this to?
"Allow me to apologize for my absence yesterday. I was indisposed on account of having contracted a virus."

Who would I probably say this to?
"Sorry I wasn't there yesterday, I got sick."

Who would I probably say this to?
"I ate your food, it was the only thing in the fridge. My bad, dude." 


Who would I probably say this to?
I must confess I accidentally ate your food, I was under the impression that it was mine. My apologies, I would happily buy you whatever lunch you would like. 

Who would I probably say this to? "I really liked your talk tonight."