I plan to travel from Israel to Jordan via Eilat/Arava crossing, go see Petra, et. al. But then take the ferry from Aqaba toNuweiba, Egypt. Here is my question-do I have to go back on the ferry or can I get back to Israel via Taba/Eilat crossing in Egypt? I thank you in advance.
Welcome, Yes, you can take the overland route through Taba.
Keep in mind, it will require that you re-enter Israel which means you'll have to pay another exit tax at Taba even though you're only in the country for a short period of time. The good news is that even when you factor in the Israel exit fee, crossing overland through Taba is still less expensive than taking the ferry.
Good luck.

If one is indifferent to 'Israel evidence' in one's passport (obviously this is the case here), then it is always cheaper, faster and recommended to travel overland between Egypt and Jordan via Israel. Obviously, this applies to those traveling on passports which entitle them to a visa on arrival in Israel, which is just about every Western passports, plus many others.

The main (some say only) reason to use the ferry is to avoid evidence of a trip to Israel in your passport. As you clearly aren't worried I'd just go through Israel on your way to Egypt.

AlanR is correct. The only ones who should be using the ferry are the following:
(1) Those wanting to be 100% certain that no 'Israel evidence' shows in their passport.
(2) Those who cannot get an Israel visa on arrival.
(3) Those who cannot visit Israel due to the laws of their respective countries.
A1 is absolutely correct - these are the only reasons to take the ferry. Additionally, the ferry is a bit rugged and uncomfortable.
If you go to Petra the same day, you need to pay more entry! about $30 dollar more.
Why not take the new tourist boat?!?
A few weeks ago I took the new ferry between Aqaba and Nuweiba. This line is only for tourists.
In about 1,5 hour we crossed the sea.
The company, Meenagate sails every morning (early!) from Nuweiba to Aqaba. And every evening from Aqaba to Nuweiba.
You need to book the ticket at least 24 hours in advance by e-mail. Online booking is not possible yet. Just sent your travel date(s), if you want an one way ticket or return (and when) plus your passport copy by e-mail (or sent this by fax).
e-mail to: info@meenagate.com
They replied to me the same day to confirm my trip.
The ticket I could collect at the harbor at the day I was traveling, same as making the payment. All went super smooth. In Nuweiba they use an other nice and clean office for customs, than the other travelers who travel with the commercial boats.

#7 (Dukka)
Interesting. However, you omitted the price. This is what I found on a Google search:
"Prices:
Nuweiba- Aqaba - Nuweiba US$ 125
Aqaba - Nuweiba - Aqaba US$ 120
Nuweiba - Aqaba US$ 85
Aqaba - Nuweiba US$ 80
Price includes marine fees and departure tax Egypt and a free soft drink and croissant offered on board. Transport of bicycles is free of charge; but should be registered when booking your ticket."