For me (as a Brit).
Mayonnaise has 3 syllables. Pajamas is said as in 'a' in father. And Pecan is said completely differently - I'd say PEE-kun. I have no word for when it is raining and sunny at the same time.
On this one though, I'd pronounce the 'ee' in been the same way it is pronounced in 'see'. Like seemingly very few of you Americans. Although thinking about it, when speaking quickly it is sometimes said the same as 'bin'.