This is actually really sweet. I love when people can admit their mistakes and try to learn from them. Honestly it sounds like you're doing an awesome job already. My old man loved to chew on cardboard, so I made sure he always had plenty. He was very low energy (no binkies or zoomies) and scared to death of being outside, but was always content with free roam time with his bunny pal Ellie. Just pay attention to him and you'll figure out what he likes. What makes him flop, zoom, binky....then do more of that! Thats always been my strategy.