Is resting heart rate the most important thing for me to gauge my heart health at home?

I would not assume that. You don't assume the quality of health in a football player who sits on the bench all day. I would look at how your system responds to meaningful physical activity/work as a better gauge. If you have a true concern get a stress test done. That is how we look at the reserve health of the heart.

The best thing to measure at home to assess how long you will live and what % of your life you will spend suffering from CV disease is to measure your BP. Heart rate is of big value in Prezi righ Measure BP. Best predictOr of how long you will live. Unless you smoke.