I think the realism factor drops if we can pause to radio our pit strategy. Sometimes the drivers can't communicate what they like because of radio problems, etc. I think the popup menu as you enter the pits is all you should get, and if you don't make any specific selections, it runs with a default set you enter before the race. You could even save specific setups (tyre type, fuel load) and just select an option, have say 3 preconfigured. Car changes... In free run mode I think you should be free to enter your garage, tune, and restart, however in a race that's not really feasible, so beyond some utterly simplistic things like downforce, no. Changing computer settings is generally done via the steering wheel if it's going to be done at all, it takes time to take off an engine cover and plug in a laptop.