I am a passenger on this cruise (Celebrity Infinity) and have the same questions as you do. I am NOT using Celebrity air but making my own air arrangements. I am arriving Santiago the morning of January 7. I want to spend one night in Santiago, then travel to the dock in Valparaiso on January 8. I looked on http://www.portcompass.com
and they have a tour that provides the transfer and sightseeing. It looks like a good deal to me. Please have a look at their tour offering and tell me what you think. We will have to put together a minimum for the tour. I am traveling by myself. I do not know anything about Santiago hotels, but the Best Western near the airport looks OK. If we put together a group, they will come by our hotel, pick us up and take us to the Infinity. Have you inquired how much Celebrity charges for a transfer? For me, the sightseeing that Port Compass is a plus.
Looking forward to hearing from you. John, Senior, FL resident, non-smoker, and speak no Spanish.