While Mr. Yoo was painting the bedroom, Mr. Kerr furniture from the living room.

While Mr.Yoo waa painting the bedroom, Mr.Kerr was removing furniture from the living room.

"You should not update your thesis statement as you narrow your topic." is false. This is because throughout writting your paper or receiving more research you may be able to add to the thesis statement, also adding on to what I said earlier its a short summary of the main point or claim of what you are writing about. Thesis statements can update or change throughout researching! Hope I helped :)