Many things affect the motorcycle state, including luggage, a passenger and a mechanical failure. The answer in every case is to first recognize that you are now riding a different bike, and second to adjust how you ride accordingly. For example, too low tire pressure causes sluggish, unstable handling and less responsive steering. Too high tire pressure lightens the steering and will wear out the middle of the tire faster.
Luggage
Luggage is a problem if it changes the weight distribution of the bike. When riding, if the bike center of gravity is at the sweet spot, right over the wheels, it takes no more effort to handle a big bike than a small one. Likewise a pencil balanced on your finger is stable if the weight is over the point, but if not, it starts to fall. On a motorcycle you adjust the weight to be over the tires as you ride. However loading one pannier but not the other interferes with this balance, so the bike handles differently when you corner. So when adding luggage, add it as close as possible to the bike’s center, and add evenly so the effect balances out. The best place to put luggage is directly behind you, where the passenger normally sits.
Passengers
Passengers that sit behind you dont alter the balance but they do increase the bike weight, and for a small bike the change can be significant. That the extra weight means you can’t stop as quickly is not immediately obvious, so be aware you need more time to stop. And this weight can move, so take it easy cornering for a while. For a new passenger, impress upon them that you want them to do nothing at all. Dont let them get on until you stabilize the bike, with both feet planted. Suggest they put one hand on your shoulder and with a leg on the peg, to get up vertical first, then slide the other leg across and sit. Its easier as a two-step process. Tell them to hold onto you firmly, not the seat or the sidebars, as a pillion passenger can fall off the back of an accelerating motorbike.
Flat tire
When a tire blows you get a big wobble, so hold the handlebars firmly, keep as straight as you can and get to the side of the road. Your riding on the rim of the tire, so none of the normal controls work too well. The main thing is, don’t panic Hold as steady as you can and get to the side of the road, out of the traffic.
Bike suddenly stops
There are many reasons a motorcycle can suddenly stop. Brakes can jam, a chain can break, an engine can fail, or maybe you just ran out of petrol. Whatever the cause, you have a few seconds to do something about it. The main thing is get off the road before you stop entirely. Even on a quiet country road, get off it! If this happens on a highway, the problem is even more urgent because the traffic is so fast. Even if you are in the middle lane, if you feel the power go, get to side right away. Dont wait. Dont worry about offending other cars. Stopping in the fast lane is a death sentence for car or motorcycle. If your bike ever loses power, for whatever reason, get out of the traffic flow before you run out of momentum.