Sequence is important in Greece. My thoughts are that a circle route gives you the most highlights and is the most efficient way to go.
Here are my thoughts based in several trips to the Peloponnese. First if you have traveled transatlantic two nights in Athens is not sufficient time to get over jet lag. You don't want to be driving before you are fully recovered. Athens needs a minimum of three days 4 or 5 is better,
So you want to do Meteora first that's OK but it is a 5 hour drive and jet lag can still be a factor.
However Mereora is well worth the effort. You need at least two nights there to do it effectively primarily because all of the Monasteries are never open at the same time.
Depart Meteora and visit Delphi. Its one of the best archeological sites around and the sequence works well. You will need a night in Delphi. Arrive in the early afternoon get a hotel and visit the museum to get an idea what was there. Note, everything is going to be on winter hours so you should expect virtually everything to be closed by 3 in the afternoon.
Next day cross the Gulf at Patras. You have a choice here go South to Nafplio or go west to Olympia. The shortoption is Nafplio with Olympia another good 4 hour drive. I know Olympia and Delphi were not in your original plan but they are major sites and worth the trip particularly with the time you have.
Olympia Delphi Meteora https://www.flickr.com/photos/stanbr54/sets/72157645469717811/
Head south from Olympia and take the time to hunt for some Venetian battle castles. This area at Pylos, Koronos, and Methoni is full of old Castles.
Peloponnese Battle Castles https://www.flickr.com/photos/stanbr54/sets/72157645468134284/
Then head east to the Mani. You might want to spend some time in Karmadili. Its a lovely seaside village and is a great base for the Mani. Personally I think you are budgeting way too much time in Gerolimenas. Maybe one night there as you do the circle route back to Karmadili.
Now continue east to Monemvassia. It is something special. Imagine spending a night or two inside the walls of a 14th century village/fortress.
Now head north to Mystras. Its just over an hour to get there and because of short operating hours you want to get there promptly because it takes a good 4 hours to do this site. That will give you enough time to drive through Tripoli to Nafplio before dark.
Nafplio deserves at least three or 4 nights because there is so much around it, Mycenae, Tiyrns, Epidavros and Nafplio old town itself.
Now head back to Corinth. There you can visit the canal but even better is Ancient Nemia (a sister site to Olympia) and still has its stadium a partially restored temple and a very good museum. Oh yes ancient Corinth the Roman town is also a very good site to visit here, From Corinth its only an hour and a half back to Athens. We always drop off our car at the airport so we don't have to drive in Athens proper.
Nafplio and Peloponnese http://www.flickr.com/photos/stanbr54/sets/72157632094108982/
This route means you have no backtracking just a continuous flow.
Having said all that I wouldn't do the trip starting in Meteora. After getting over jet lag in Athens for a few days I would drive to Corinth for the ancient sites there. They can be done in about 3 hours total then south to Nafplio. Its a delightful seaside town and is perfect for more relaxation and the great sites nearby which can be done at your leisure as energy levels increase. I would spend 4 or 5 nights here. Now do the route the opposite way to Mystras. Don't bother stopping in Sparti just get to Monemvassia after Mystras. Now west toward Karmadili, the Mani and continue to Pylos for the castles and on to Olympia. Now head north and east to Delphi and Meteora. You will be dong the long drives at the end of the trip rather than the beginning.
Hope that makes sense.