Do you think that small states like RI, DE, and CT should join other big states?

No, that's silly because saving money on administration costs won't outweigh the fact that the administration as a whole is much less efficient. It would be harder to manage a bigger state vs a smaller one. State boundaries also help to seperate people in different area with different concerns. If your idea played out and eventually all the states became one, then you lose a bit of representational democracy, which is what our system is.