I wear my black FitBit to work every day - no one has ever freaked out about it. I think you'll be fine.
I totally agree. As long as you dont wear a pink band or something, I cant imagine who would be bothered.
I generally wear plastic sports watches to work along with a suit. I'm currently wearing a Polar V800 (I actually own a really nice Omega Seamaster but rarely wear it). I'm currently leaning towards the SS apple watch with a black sports band, possibly buying the stainless link bracelt later.