This could sound a little flippant, which is not intended. The pilots whom I have seen and flown with, who would appear to trying to be perfect, seem to me to be the ones who have the hardest time. Pilots having a hard time are more likely stressed, and thus opened to making mistakes.
I am required duing my work to consider the possible effects upon pilot workload, of changes to aircraft. Yes, the flying environment has complexities, which sometime can test one's capacity. To account for this, I always fall back to what I was taught in my very early IFR days: "Aviate - Navigate - Communicate" in that order. Everything you do while flying a plane can be described as one of the three foregoing activities. Once you know which one it is, you know what order of imprtance it holds during your flight. If doing the first safely, then maybe the second, you run out of capacity to accomplish the third right then, oh well, someone is going to have to understand. That's that!
If you are trying to do everything at once, you're going to miss something vital. There is an excuse for a pilot not reporting turning base, if failing to make that report assured that the wheels were extended. If you land with the wheels up, saying you were talking on the radio is not going to be accepted as an excuse. YOU must determine what is to be done to safely accomplish your flight.
I've been flying for thirty years, so you'd think I'd be able to handle talking on the radio. Recently, while flying a helicopter at a controlled airport, the task was so intense (longlining training), I could not manage the distraction of the radio, so I turned it right down. I aviated safely, and was very careful to navigate so as not to move anywhere which would create a reduction in safety for all other aircraft. I did not communicate. It worked. Saying that I crashed the helicopter because I was talking on the radio would not come across well at all!
If the flight you are considering, is going to involve complexities beyond your capability - weather or airspace (traffic), a perfect pilot (while still on the ground) would rethink the flight at all, and perhaps get help. If you have decided that you can manage the flight, the aircraft you fly will come with a checklist, I don't need to tell you to use it. Take paper and a reliable writing instrument, and take notes (when you are safely able - this is communication) of what ATC would like you to do next. Mentally extract the important elements, and read them back to ATC. That will increase the likelyhood that you have retained it and will remember it, and now puts the onus on ATC to assure that what you read back is what they intended.
As for glide distances while flying, The flat surfaced earth is the single engine pilot's utopia. It's the huge crop fields in midwestern North America, I've flown over them, you could land safely most anywhere if it quit. Other than that, you will spend a lot of your flying career flying over surfaces upon which a forced landing is not going to work out well at all. the charts show these surfaces well. If you don't want to fly over them, don't. If you choose to fly there, prepare for the risk. Carry whatever you need (lifejackets?) and take the extra care that you are flying an airworthy aircraft, in suitable conditions of flight. I have had 4 single engined aircraft engine failures in 5000 hours. Three were related to the affects of ice, one to the affects of mice (aircraft not airworthy!)
Worry less, allocate your attention appropriately, and follow your plan (which includes checklists)
Fly safely, and enjoy.
Pilot DAR