First, carbon. You already know you don’t need it for your casual weekend pursuits, because you’re not counting ounces the way a professional road racer would. But to quote an article from Velonews, “Remember that professional athletes operate in an entirely different environment than the rest of us. They are all very close to each other in terms of fitness, and they are also all very close to being the absolute best a human being can be. In short, you’re much better off upgrading your legs and dropping body fat through proper training and diet.”
As you mentioned, it is surprising how often you can get multiple flat tires on while riding, particularly on longer sprints. The tip about bringing a patch kit in your bike repair kit can be incredibly helpful if you’ve already had one flat tire. I agree that all you listed seems like an awful lot to carry, but it’s always better to be safe than sorry, isn’t it?
Let me go ahead and get the bad stuff out of the way. First of all, this stand is NOT the same level of quality as something you would find in a bicycle shop being used for the shop's repairs. it's quite a bit more flimsy, and the grip likes to rotate if you don't get the bike's center of gravity just right. The tool tray is also made out of a rather cheap plastic that can break easily at the rim. That being said, this stand is perfect for home users and makes mundane tasks like fixing a flat or cleaning the chain much easier. It easily holds my Raleigh Merit 3, and I don't worry about the thing falling even if the grip tilts a bit. The stand significantly shortened the time I needed to change an inner tube on my bicycle, and made me less worried about damaging something on the bike by jury-rigging a stand out of whatever I had lying around.
Broadly speaking there are two major wheel sizes – 700c for road bikes and 26 inch off-road wheels. However there are a whole variety of older, less common wheel sizes and of course fold up bikes have much smaller wheels altogether. Repairing a puncture is not an emergency! It’s a basic procedure that every cyclist should be able to to perform, but doing it correctly involves more steps than many people realise. Wheel building is often seen as the most artful skill in bicycle maintenance, and separates the professionals from the amateurs but that doesn’t mean you should consider it out of reach. Truing a slightly misaligned wheel is a cycle maintenance job that almost any cyclist can perform.