He sounds a real handful but a loving and active child. I'd set up a reward system with clear guidelines about what is and isn't allowed, and with a simple request that if he gets an idea about doing something risky he talks to someone about it first. If he manages this (and it's possible he may not) try not just condemning hs ideas out of hand but discussing safe ways he can do things. You could do a star chart with a big reward at the end of any week when he manges to keep to the rules. But I fully admit it might not work.
You could also set him challenges, do physical things with him and experimental things.
Had we not been in lockdown I would have suggested enrolling him in a youth organisation like cubs, or getting him swimming lessons. Could he perhaps put up a tent in the garden and build himself a camp? Has he got "The Dangerous Book for Boys" ? He's a bit young but some of the projects in there might interest him www.amazon.co.uk/Dangerous-Book-Boys-Conn-Iggulden/dp/0007232748/ref=asc_df_0007232748/?hvlocphy=9046781&linkCode=df0&hvptwo&psc=1&psc=1&hvnetw=g&hvadid=310991231187&hvpone&hvlocint&th=1&hvpos&hvdev=c&hvdvcmdl&hvqmt&tag=gransnetforum-21&hvtargid=pla-565724266703&hvrand=11568738588346444957
Recommendations please, for a stopover on the way to Loch Tay