You would not want to call yourself "Wasabi" because it would make people see you with stereotypical eyes. Wasabi is known to come from Japan (or to a lot of Americans, simply Asia). When people hear that your name is Wasabi and they see that you are Asian, it will make it easy for people to make fun of you. It is only because of the ignorance that fuels stereotypes that this happens. Otherwise there would be no problem with the name. For example: A stereotype of people with blond hair is that they are stupid. Another name for this is to be "airheaded" If someone decided to call themselves "Airhead" simply because of the candy name, they would be inviting people to treat them like a stereotypical blond--to treat them like they're stupid. On the other hand, if you wanted Wasabi to be a nickname for you that only your friends call you, that should be fine, because when your friends call you Wasabi, they will not be doing so in a mean way.

No. It's a stupid name. Remember, a lot of people don't like the taste of wasabi! You don't want your name to remind people of something they don't like!

maybe it's a good japanese name?

Wasabi is a nice name for a glob of green gunk. :P

For a plant yes - and maybe for a pet - but not for a human. It would be ridiculous.