I feel strongly about the “free and correct”, due to good instructors, and much reading of accident reports. When flying light GA planes, my technique for a control check is to move full aileron, then control full-forward to full-aft and back, reverse the aileron, repeat the pitch.
When doing a run-up and final checks prior to takeoff in a 172, I had full aileron and pulled back, only to have something catch behind the panel. With the typical winds here in the Midwest US, stiff crosswinds are common, requiring a lot of aileron while pulling to flare. I can imagine the above problem preventing me from fully flaring, and pranging the nosegear. I heard that a bundle of wires was restricting the pull, but only with a lot of aileron. I was amazed- and stunned- to think of all the pilots that had been flying the aircraft before me that had not caught the problem, and flown with it.
A well-known lawyer in my city died in a takeoff crash, post-maintenance. They found that, the more he trimmed nose-up, the more the plane nosed down. I believe it was a Baron, and I understand the elevators can be installed on opposite sides on the type, so the trim worked in reverse. Due to a post above, I will now conduct a full-trim exercise on the ground on my preflight checks, too.