Thank you Qwerty, for pointing out that a Bonsai is a plant. When I read the post, that's the first thing I was thinking. (And just to educate you, "banzai", spelled differently, was the Japanese war cry you were referring to, and it approximately translates to "ten thousand years".)
As for "bazoom"...it doesn't sound anything like a plane. That's probably the least likely word a child would associate with the sound of a plane, regardless of what kind. Most children I've heard actually make engine noises. And probably most children wouldn't tell you that "bazoom" is the sound a plane makes if you specifically asked them what the word brings to mind.
"Hop", even repeated, does not sound like a gun firing. Your imagination is running wild and you're inflciting it onto your child. "Hop" is what children are told bunnies do. What will you tell your child when he/she see a little rabbit hopping by in a cartoon or in a book? Will you avoid using the word for fear that it may sound like a gun firing? If that's your line of thinking, then the word "pop" would also fall into the same catergory, as well as "ba". All these syllables repeated rapidly would drive your mind into overdrive, I believe.
You're hearing things that aren't there. Lighten up with your perception and paranoia. Your child will be fine (hopefully) if you actually let him/her enjoy being a child instead of putting ideas into his/her head about misconstruing innocent things/actions/sounds.
Proud and loving Mommy of my very own Baby Poof.