While silver would be interesting, it wouldn't be ideal.
For each specific example you provided, we'll be assuming an alloy of silver, as normal silver is just too soft:
Automobiles, Aeronautics, and Shipbuilding: I'd say silver is a poor choice for these when compared to iron, and especially when compared to aluminum. It weighs too much for Aeronautics in general, as a frame built of it would be almost 1.5x heavier than iron, and Aeronautics is all about shedding weight. As far as shipbuilding goes, it seems possible, so long as the ship is built with greater weight in mind, as iron already doesn't float normally. It would also be a poorer choice for automobiles, as the increased mass would make accidents more likely and more dangerous. Additionally, silver has a worse tensile strength than iron, so those automobiles would be more likely to snap than iron. Additionally, air filled tires would be even worse on these automobiles, and axles would have more issues with alignment as the force on them is greater.
Building construction and as a structural/building material: Well, due to silver's increased mass and decreased tensile strength, it would also be worse than iron, so while it should be able to create frames for buildings, they would all be shorter than ones with steel skeletons. Tall buildings not only have to deal with the weight of a frame, but with wind pressuring them from all sides (and silver's tensile strength means less bending than iron's), so I'd expect a large decrease in height.
Firearms, though, are a different story. Silver would be perfect for bullets - you could use almost any metal, but more readily available ones are better. There's really no reason lead is better for bullets than many other metals, other than tradition by this point.
However, silver would be amazing as a coating for many materials. Pure silver is actually fairly tarnish resistant, with alloyed silver having tarnishing problems. Why is this good? It's basically perfect for a protective lining for pipes, beams, and anything exposed to water or other elements. So in a world where silver is common, I'd expect it not to really replace many other metals (unless they were very rare, like swapping rarities) but to coat metals exposed to the elements.
Also it's antibacterial, like copper. However, as bacteria do need some copper for some proteins, it is not impossible for them to evolve resistance, as they already have some copper processing ability. Silver, on the other hand, is basically alien to their biology. They'll have about as much fun adapting to silver as we do with lead. (not impossible, but far less likely than copper)
In essence, it's bad for structure but can be great for coatings.