Whoever is worried that opening an umbrella in the house is bad luck should worry first about the reason they'd need to open an umbrella before worrying about any bad luck that may come, because it's likely already bad luck that they need to open the umbrella in the first place.
And that whole having to throw salt over your shoulder after spilling salt thing? WTF? It would cause you to be in an endless loop, because if you threw salt over your shoulder, you'd have to do it over and over again because the salt just falls behind you to the floor. Unless, of course, you hold your plate behind your back where you'd be throwing the salt. But that would be quite a feat to accomplish.
And that whole having to throw salt over your shoulder after spilling salt thing? WTF? It would cause you to be in an endless loop, because if you threw salt over your shoulder, you'd have to do it over and over again because the salt just falls behind you to the floor. Unless, of course, you hold your plate behind your back where you'd be throwing the salt. But that would be quite a feat to accomplish.