At 50km you might get breaks so you can see clouds, not sure. That's it. But no chance of seeing the ground. That might appeal for a few minutes, but I think I'd be content with seeing it from an observation dome
Leaks wouldn't be a big issue because the pressure would be similar. You'd need to fix them, but you won't have the air suddenly rushing out.
I'm assuming you mean sealed buildings inside the blimps here, because you'd have nowhere to walk to on the outside on account of being 50km above ground. In which case you probably wouldn't need anything in the case of a leak.
That's what I meant. No need for fast closing bulkheads, just get everyone out to another sealed building inside the same aerostat at whatever speed it takes them to walk to an exit and get in their protective non-pressurized gear. Outrunning gas diffusion is easy.
50km up with certain death if you can't get back to the blimps because dropping down to the surface would be lethal? In fast moving wind systems? Yeah, no thanks.