To try and answer your first point, what’s your dispersion at the given distance, with that lie and that club? If you know, through experience/practice, that you generally stuff 8 out of 10 5-irons within the area two extended fists cover when they’re held out in front of your face, and you generally get 150 out of your 5-iron, then your dispersion for those 80% is, (10 degrees per fist × 2 fists x 5 feet subtended per degree at 100 yds × 1.5 (150/100)) 150 feet. How big’s the green?
Adam Young, as usual, has a few great blog posts on visualizing your dispersion, then overlaying that on your target zone to get as many of the shots on it as possible. Usually, for hacks like us, aiming to the middle of the green, with enough club to hit the back of the green, works. The shotgun pattern of shots covers the most area of the green that it’s going to, that way. If you know you never, never miss right with fade/cut/banana-slice action, then put the target focus on the far right of the target area, and let your natural miss cover more of the target.
Holy s%/t, do I feel that feel about what’s the worst that can happen. It can be absolutely soul-crushing to flat miss around the green that way. Dangerous for your playing partners too. My suggestion, borrowing heavily from our host, is to have One True Shot around the green, and master it to the point where you can at least hit the damned thing onto the green. It can be a chip, it can be a flop, a pitch, whatever, but get it to where you can hit the ball, from wherever off the green you are, somewhere into the soothing fuzzy swimming pool that is the green. Then when you can do that automatically, focus on improving things.
But get on the green.