No fire extinguishers at my house (bad idea). All appliances have timers on them, so nothing can start a fire due to being left on/user error. No carpets only rugs and hardwood floors also minimizes fire risk. Roof was redone with fire resistant shingles. Getting a very cheap security system that will notify me via text if it detects smoke. Prevention over redundancy.
I'm not heavy for my height (180), but when you consider my bike weighed about 120 or more plus the basic hand tools I carried and topped out at over 50mph, the forces have to be similar. And yeah, I did some very hard stops that made both front and rear brakes too hot to touch... If the rear wheel was still on the ground. I used to run pedicabs as well... Coming down a hill with 800lbs worth of customers, bike, and me never caused tire shifting.
My point is that tire shifting has to be addressed as a problem and solved by fixing the problem. Buying a foldable bike stand to carry with you for every time your tire shifts will onl make the problem worse - for starters the load you carry will be 30lbs more. Have you considered a center kick stand?
Now for the problem of tire shifting:
If you are running chrome plated steel rims, I suggest you switch to aluminum rims because the coefficient of friction of aluminum is more than double that of chrome, and about 50% higher than steel. Same reason why people using rim brakes prefer aluminum rims. If you're concerned with the strength, a V-section double walled aluminum rim will be just as stronger than a single wall steel rim with half the weight.
What tires and pressure are you running? I'm thinking you need to run higher pressure tires.. I ran kendas at 45-55 and you can also get cst cyclops tires cheap that will handle 65psi. Low pressure tires will move sometimes. aluminum rims and high pressure to push the tire against the rim should solve your shifting problems.