Ok, so a quick update...
I did a little research at work once my wife called me with the problem before she took it in. It all pointed to what I stated in the OP. When they called me to tell me what they saw and what they recommended, I told them I would discuss it with my wife and let them know. Something just didn't feel right about it. I got home and did some more research (forums, auto sites, etc) and it all pointed to what I stated in the OP.
I called them again today and asked some more questions to see if it all had to be done or if they felt it was one thing over another. He stated that the plugs could use a change, but I should be OK for another 20k or so miles (about where I'd think it was time), and that they felt the fuel system cleaning is what was needed. I prodded them on what all that entailed, and he went into the specifics. Seemed to be more than just dumping some fluid in the gas and letting it go. I still didn't feel comfortable with it because I didn't think this was what was wrong with it. I asked if they had been able to duplicate the problem, and he said "we've driven it a few times and it never died on us." I asked him to repeat himself, and he stated "it never died on us." I told him that it never died, it just lost power and would barely go. He said "so, it went into limp mode?" I told him yeah and he said "your wife told us it died." He said it wasn't throwing any codes, and I told him the little wrench showed up each time it happened and that she was able to turn the car off and it fixed the issue. He told me they would drive it some more and see if they could duplicate the issue. I told him she drove maybe 10 miles yesterday and it happened twice.
As soon as he hung up, I called my wife. The conversation went like this:
Me: Hey, what did you tell them when you took the car in?
Her: I told him it began sputtering.
Me: Did you tell him it died?
Her: He asked if it died and I told him "yes."
Me: You never told me it died.
Her: What does that mean?
Me: <internally>ARE YOU ****ING KIDDING ME?!?!?!?! YOU TOLD HIM IT DIED WITHOUT ****ING KNOWING WHAT IT IS?!?!?! HOW DO YOU NOT KNOW WHAT DIEING MEANS?!?!?!</internally> It's when the car shuts off while driving or sitting at a redlight.
Her: Oh, it never shut off.
Me: So it never died?
Her: No.
Me: Ok.
She then began getting a bit defensive and saying that next time she will leave it on side of the road and let me deal with it. I had to tell her that I wasn't blaming her and just trying to get the facts, because they do matter, and that I didn't want to shell out hundreds of dollars when we're not sure if it will fix the issue. I would have taken it in, but I was at work 40 miles away and she didn't want to wait until I would be able to on Friday.
Anyway, I got a call back from them this afternoon saying that it happened while they were driving it and were able to get a code pulled, and it was the throttle body. It appears to be some kind of sensor in it. He said that he checked with Ford and there wasn't a recall or anything on it. I told him I had saw they extended the warranties on them for other Ford vehicles for that model year, but the Edge wasn't on there. He quoted me $204 out the door for the fix. I figured that was reasonable for me not having to go find a sensor and try to find time this weekend to do it.
I gave the shop the benefit of the doubt for 1 reason. I've taken my truck there three times with issues (all sensor related: park neutral, crank shaft, and fuel level) and they always came back and told me the problem was what I had concluded it could be by doing my own research. Only once did they have a code to pull. They have also quoted me in the ballpark of what I was reading online that others were paying for the repair and never tried to up sell me on anything. They did recommend a brake job be done within the next year last time I took it in, and when I did the brake job last month, it was time.