That skipping disc usually means scratches or a bad press, so try a cheap disc resurfacer before you give up on the set.

Heard a pitmaster say "just leave the lid closed" and I ignored that for way too long.

My uncle walked 5 miles a day for 20 years and dropped dead at 70 anyway, so I stopped trusting step counts as some magic number. For the cart thing though, my old Fitbit always read way low when I was pushing a buggy, something about the arm not swinging.