A few Ritz Carltons may have been the benchmark long ago, but certainly since the chain was acquired by Marriott, that has ceased to be true. Overall I wouldn't categorize RC as the highest status luxury hotel chain. You have nothing to fear if you use ommon sense, no one will be checking that you are using the correct fork.

I usually tip a hotel complimentary chauffeur what the taxi fare would have been, but maybe I am being too generous. I only tip concierges if they do something significantly out of the ordinary for me. Just getting a restaurant reservation doesn't rise to that standard, for example, unless it is for an "impossible to get" restaurant.