Yes. In your example they mean the same thing (assuming “I” is “him”s boss and is asking “him” to take out the garbage in the course of his work for “I”).
Absolutely! If I say to my daughter, "could you please clean up your toys?" It is technically a question so I can say "I asked her to clean up" but in actuality, it is a nice way of telling her what she has to do, so I can also say, "I told her to clean up" and it would be true.