Almost any airport has an ATIS (Automated terminal Information Service) or AWOS (Automated Weather Observation Service) which broadcasts weather and other relevant info over VHF and UHF radio frequencies. The machine can also be reached by phone. (Denver Int'l is 303-342-0838 ).
Yes, changes in density altitude will effect control surface response. This is exhibited by the difference between Indicated Airspeed and True Airspeed. The difference increases as Density Altitude increases. All else being equal, aircraft performance and response will be the same at any given Indicated Airspeed, regardless of True Airspeed. One advantage to higher Density Altitudes is the reduction in Parasitic Drag (wind resistance) because the air is thinner. So although engine performance drops as you climb, the airplane itself gets faster. A commercial jet airliner's sweet spot is typically 35-40,000 feet, a C-130 likes 22-28,000, depending on weight, and most piston singles do best between 8,000 and 15,000.
OK, enough gee-whiz pilot stuff, this is a car forum. If you think this stuff is interesting, I highly recommend adding "Learn to Fly" to your bucket list.