I don't see that FC shirts with spread collars should be worn with chinos!
IMO, chinos are MUCH too casual for that....
I wear French cuffs with no tie very frequently and have been doing so for many years and everywhere I have lived at (Amsterdam, Texas, Los Angeles and now in Silicon Valley). Rarely did anybody make a comment about them, and as far as I can recall they were all positive. I am in my 50's, in the technology industry and have seen a number of people dress this way over the years.
+1 I live in the U.S. and you can wear a cheap $30 french cuff shirt from Macy's and people think you're some rich snob. Depends where you are, but where I live I see very very few people ever wear them. But where you're at it should be a different story, so I would say wear them.
What about in an air-conditioned office? The same issue exists with ties - you shouldn't wear one without a jacket, but the jacket often comes off during the day. I look at my jacket (sometimes on the back of my chair) as a tether. I can only go so far away before I need to bring it with me. The bathroom is OK. A meeting room might be OK. A different floor is not OK.