Another Italy Train ticket question -- Edit: more questions as I try to book

Trenitalia and Italotreno run the trains and sell their own tickets. All the others are re-sellers. Some re-sellers are reputable like ItaliaRail, some aren't. The best site is the cheapest one with the best T&Cs, I think this means the sites of the railway companies but some could disagree.
Italo's senior fare is explained here: https://www.italotreno.it/en/train-offers/italo-family#italo-senior

Make a fake purchase on italotreno to discover if they make you choose seats or not. The great part of italo's customers isn't worried about choosing seats, they can always ask other passengers to switch.

You are right, Napoli Centrale is Napoli Cle. Napoli P. Garibaldi is the underground station in front of it.

Thank you Dario. As always, I appreciate your help.

The others that you have named are not consolidators - they do not buy lumps of unused seats and try to resell them - they use the same seats as the train company and sell them on, like a travel agent. Like a travel agent they take no responsibility in case of any problems - you tickets form a contract between you and the train company.

So why not deal direct - I always have done- and get all the help and recourse from the company operating the train? It looks confusing, and Italo and Trenitalia have different names for their products, but underneath it is all pretty simple really and you can get what you want. Using either you can do the entire transaction online in English.

At the moment for your date and time Trenitalia is offering the 7:30 for both of you for €115.80 Super Economy (to save €7 and use the Freccia Senior fare you would each need to have a CarteFreccia) , the next train at 8:30 is €121.80 for both of you, but if you can wait a little longer you can both go for €99.80 at 9:15 or 9:30. All these journeys are to Venezia Santa Lucia and don't involve changing - journey time 5 hours and 5 minutes.

If you go to .italo Treno, the 7:50 takes 5 hours and 10 minutes, €45.90 each = €91.80 for both, in Smart (the cheapest are gone, and that is cheaper than the Senior fare.

The 9:45 takes 5 minutes longer and is going at €65.90 x 2 = €131.80 for both.

So which one appeals? The fares won't go down, and as they sell out they will go up. Remember that for both companies these are cheap fares and come with plenty of restrictions, particularly about refunds.

Try trainline.eu

They have no booking fees and are reliable. They show tickets on the Trenitalia 9:15 and 9:30 Frecce trains for €49.90. The 9:45 Italo train is €65. Lots more on offer for May 20 as well.

I did not put in ages but I do not believe there is a Senior discount off the Economy fares, just the main ( Base) fare.

We bought tickets for train travel in France from Trainline last summer and it was smooth and easy.

I always check:
https://www.seat61.com
before booking any trains in Europe. He explains which sites to use from places outside Europe. I have used:
https://www.trainline.eu
with no issues from his recommendation.

As long as you are not going to pay taxes in Italy, you don't need to register. On trenitalia.com, registered customers receive a fiscal invoice via e-mail, that's all.
I'd rather follow italotreno on Twitter, it seems they publish discount codes once a week.

Use another e-mail, then forward the pdf tickets to the @q.com address. To be 100% safe, You could also print-screen the purchase page on Trenitalia.com that shows the PNR number and the other codes .

I'm a big fan of loco2, it's user friendly for us Americans, and they don't charge extra fees.

I last bought tickets from loco2 in 2017. I don't know if this is still the case, but at that time you could have loco2 email you when the tickets you wanted were available for purchase. You don't pay for the tickets ahead of time.

As I've removed a few posts to take the edge off, this is a reminder that all opinions and experiences are to be respected in our forum. Make your case the best it can be and avoid rejecting others' advice. Otherwise, readers focus on the argument which distracts from the advice. We trust that everyone reading along can make the best determination for themselves when differing advice is given.

Thanks to everyone for the help they give to others.

I tend to prefer Trainline.eu as the website is very user friendly, and they sell tickets for the two main rail networks in Italy as well as many others in Europe, at the same price as the rail networks. They also have a smartphone app., which makes it easy to book tickets on the fly. It's necessary to register on the site first, including payment details, but once that's done it's very easy. I've also found their customer service to be very responsive, should any problems occur.

Thanks Everyone! I just bought tickets on Trenitalia. Premium was cheaper than Standard. The price went up after I bought. But it changed four times while I was deciding and then went back to the original price so who knows.
Now on to renting the car.

I used Trenitalia when I was purchasing tickets for Rome to Naples and back. Super easy.