I think (that is if April Fools day is celebrated outside the US) that non Americans have a sense of humor. But if you do something like that in a mall in the US, you will probably have security called.
A few buddies and myself drove in backwards through a drive-through at a fast food joint. The manager came to the window and nearly had a stroke from all the yelling he was doing.
I also made an armpit fart noise in gym class, back in 8th grade, when we were stretching our legs, and it was timed perfectly when the gym instructor bent over.....she called my mom. I served a detention.
It seems to me that no one has a sense of humor. It's all too sterile in the US. Because people are anal about being offended, sued, or harrassed. There is a mass hysteria of that BS. Quite frankly it all boils down to common sense and a little humor.
I don't know how it is in other countries, but this is how I feel about it in my area.
Re: your ideas
All are pretty funny, except the "jump on top of the piano and start dancing" skit, that is quite frankly scary. Don't wear high heels, and you or your associate better not be that heavy. Because if you break it, you bought it.