Was Majin Buu able to turn people into physically anything? Majin Buu has a beam where he can turn people into chocolate or assortments of candy. In one episode he turns an old man into a carton of milk. In another he turns a village of people into a white clay? like substance to make a house. Does this mean he is able to turn people into physically anything, say for example.. a gun or money?
It's not clearly explained in neither manga nor anime, but my understanding of this ability is that he can turn anything (remember he turning rocks into candies?) into lifeless stuff, so turning people into monkeys might be too much for him.

I mistook monkey for money. Since gun and money are lifeless stuff, I would say yes.

PS. People turned into lifeless stuff may still be conscious depending on how strong they are, for example, the fusion of Goku and Vegeta was turned into a candy yet still can fight, and Uub was turned into a chocolate by his own beam yet still can turn himself back.