1.) If a tire "blows", it's usually because it has been run low on air. Low air pressure causes unnecessary flexing and heat build-up. Eventually, the heat causes the materials to sperate and you get a "blow". Likely cause was a slow leak that you didn't know about. Please! Check your air pressure regularly!
2.) The wear on the inside edge of your tires is likely from misalignment or too much camber. Yes, this can happen with a solid axle. About the only way I can think of to remedy this is to have the axle bent. A shop that repairs over-the-road trucks can do this - that's how they align truck axles. Or, you could replace the entire axle. It is likely that, somewhere along the line, you or a previous owner (if there was one) may have hit a pothole or a curb hard enough to bend the axle just that tiny little bit it takes to cause that kind of wear..... Putting on a radial tire will sometimes solve this problem as well if it isn't too severe. Radial tires have more flex built in and are more forgiving.
Sorry to say "operator error" in both cases, but it usually is.
Or, as Pat Goff would say: "It's not the arrow; it's the indian!"
me!