Athens & The Heart of Greece iin 14 Days - Three Questions

How easy is it to communicate with locals inasmuch as we do not speak
Greek?

All people who work in tourism (hotels, restaurants, services) speak English. In restaurants 9 times out of 10 the menus are available in English.
However, it is good to know a few basic words in Greek like: hello, thank you, goodbye, you're welcome.. etc.

I often recommend this video from Easy Greek which is one of the best I know and where you can pick up these few basic words and practice pronouncing them. (no need to learn all the words, expressions)

https://youtu.be/FYtqqfJdeIs

Do you recommend we take a taxi from the Athens airport to the Hera
hotel, or book transportation arranged by the hotel?

The hotel will do nothing better than book a taxi for you, and probably charge you more than the normal price.
The cost of the taxi Airport→Athens is a flat rate of 40€ (during the day), tolls and luggage included.

Either you take a taxi at the taxi rank at the airport or you can also pre-book it with for example Welcome Pickups. It will cost 3 or 4€ more than the flat rate, the drivers speak English, he will wait for you at the airport with a sign with your name.

https://www.welcomepickups.com/athens/

The National Archeological Museum (NAM) is huge, you can spend hours there among thousands of artifacts, pottery, statues, jewelry, objects of all kinds, etc.
To visit it reasonably plan at least 2 hours.

It is not in the center of Athens, from the Hera Hotel plan about 15 to 20 minutes by taxi or bus.

https://www.namuseum.gr/en/

You can buy tickets online in advance but there are usually not many queues at the ticket office

I can only speak to the language part as the museum visit was at the beginning to the tour when we took it 10 years ago. At that time lots of Greeks spoke English and we never had any trouble with that. We took the metro from the airport and got turned around coming and a kindly gentleman of Australian origins pointed us in the right direction.

It’s a fabulous tour.

Regarding the language question, if you install the Google Translate app and link it to your phone camera you can hold the camera over Greek text and it will display the English or other language translation. Good luck!

I checked my scrapbook for that day on the tour. I have a photo of the day's schedule. It says we were to catch the hydrofoil at 7:05 and we would be at the Archaeological Museum at "9:30ish". I do recall we had all afternoon free in Athens. Hope this helps. I loved this tour.

Have you bought the Rick steves GUidebook? If not, Tsk Tsk, but your llibrary has a copy ... and it includes a splendid "Survival Guide Phrase List" ... Of all the GUides, this is THE Most useful & I've photocopied it for every newbie I've traveled with. What makes it so good is that he gives the phonetic pronunciation and shows in Boldface, what syllables to stress. Of course, these days, almost every Greek under 40 speaks some English (schools start teaching it in Kindergarten!). But Greeks always appreciate the effort when you use a few words... in a cafe, instead of "Red wine," try saying "Krah-see Kokkino" and the waiter may respond "Bravo!" And words like "Omorfo" (beautiful) and "Nostimo" (delicious) are also well-received.

On our tour, my notes and photo of the day’s itinerary shows, we took the 7:20 ferry from hydra. Arrived in Pireaus at 9:20. Our bus drove us to the museum. We visited the museum for several hours. We arrived at our hotel by 1 pm.

Thanks for the responses. Much appreciated.