so two things
the bicycle trailer setup in the picture is just a modified kid trailer that somebody put a white PVC rack on, tongue looks like a piece of aluminum electrical conduit. You could make the tongue detachable with clevis pins so it store well. Get a canadian tire small steel toolbox, bolt it to the trailer and lock your wallet in that (mostly just take whatever debit/CC card you need so when it does get lifted you dont loose everything.
The sidecar platform thing was used in the UK and Europe for decades for cheap city deliveries , if you get serious about that a place in Acton , Ont . OldVintageCranks are the gurus of sidecar in Ontario. They can steer you the right direction. Sidecar is not required to have brakes, most new ones will but for 100yrs not so much
Option 3 , move west to Oakville , I'll set you up at an decent yacht club. Store your surfer and come crew on my race boat, I need help. I own a DN iceboat, two days a year in a good year can it be used. But you can do 50mph in pretty small breeze so worth the wait.