Yes, I believe you are in the minority. Mostly, people fold the sleeve outward rather than tucking them under. In warmer climes, long sleeves can also be folded over multiple times until it rests just above the elbow. That could be difficult to do with the inward approach.I am struck by the way he has folded his cuffs, turning them under, rather than folding them to the outside. This is the way I fold my long sleeve shirt cuffs, but Ralph's model and I seem to be in the minority on this approach...yes, no?
I have always loved that particular herringbone. It is an exceedingly hard color to find.
I agree, jeans or khakis are fine with tweed jackets. It is the rest of the ensemble that calls for trousers of the same fabric ( a three-piece suit) or perhaps grey flannels, although I might avoid the waistcoat if were to pair the jacket with flannels.I think indigo jeans with the jacket are fine, but nit with a waistcoat and tie, too.
I like dressier topcoats with casual outfits, which is the chief way I wear mine now that I'm retired. Never owned a polo coat though.Away from all the affectations you rightly note (he even has a hint of Bobby Kennedy to him), I did like his outfit as a nice way to wear a Polo coat as part of a casual outfit.