Best options for travel from Amalfi to Cinque Terre

While I am a nature nut, I think I would appreciate a night in Naples to break up all of the small village time, so if you have time, sure! But the train times will determine what time you need to be in Naples--check schedules on the Trenitalia website.
It is a long journey, so you might want to break up the trip en route instead.
You can also take a ferry to Salerno train station or use a private driver if you are bypassing Naples.

You'll be closer to trains from Salerno than Naples. I'd take a private transfer or ferry from Amalfi to Salerno and trains to CT from there. The train station is walking distance from the pier.

You're right this will be an all day travel event. I agree that ferry to Salerno and then fast train from Salerno to Rome is probably the best solution. If you don't want to take a bus then private transfer from AC to Naples and then Naples train northward is probably the only other reasonably fast solution. (You could private transfer or ferry to Sorrento and then local train or ferry to Naples but you're adding several transfers to what is already going to be a long day will multiple transfers.)

From Rome whether coastal train to La Spezia or fast train to Florence and then local trains to La Spezia depends on schedule but you're going to have to change twice - maybe three times - between the trains if you include La Spezia to CT. When researching routes I would use La Spezia as the target station because if you use a specific local CT station it may alter your results. If you get lucky your train might also stop in the CT town you want but I would plan on getting off in La Spezia and then switching to the local train.

I, personally, would consider breaking this trip up with a stop in the middle so not to spend a whole day on travel. Since one of the options is Rome train that runs up the coast you could choose a coastal town to stop in and break the journey up, but it's your vacation.

Hope that helps,
=Tod

I would also suggest a train from Salerno, and a ferry from wherever you are on the coast to Salerno to leave. I would definitely pad the schedule a bit, just to make sure your ferry got you there in time, but if you ended up with a LOT of time, there are plenty of bars and cafes near the station to rest (or you can shop on the corso! or walk on the lungomare!) and refresh yourself. I would ALSO suggest to grab a panino and even some mozzarella di bufala from la Contadina on the way to the station for the trip :)

I appreciate everyone's suggestions, as this will make my planning easier! Thank you!