Sorry for your loss.

Density altitude claimed the life of a dear friend at Salt Lake City a few years back and ingrained in me—just a student pilot at that time—a healthy respect for density altitude and operating up near gross weight.

Operating any airplane is inherently more risky than sitting in your swivel chair, but you take measures to contain the risks. That is the essence of planning and training.

Other thoughts:
Haste has killed more pilots in aviation than any other factor—accidents happen because people are in a hurry, in one form or another.

The most dangerous kind of aircraft is one fresh from maintenance.

Legally current does not mean proficient, and vice versa.

Flying a big jet (or big radial) takes considerable malice aforethought, but you generally have enough thrust to get away from whatever it is you are into and go off somewhere else while reconsidering your options. On the other hand, flying light airplanes, especially IFR, takes a certain amount of cunning. (If thunderstorms are about and you don't have storm avoidance equipment it also might take a little bit of luck.)

etc.