The Expedition has the highest towing capacity of anything in its class. Not only that, but it does it with ease. I have only towed over 8K with it twice, but it handled it VERY easily. I have towed 5-6K MANY times, through the East Coast mountains(Not even close to the west, but still can push a lessor vehicle), with ZERO issue. Heck with the towing package it can pull more than some of the competitors 1500 Trucks. So it has PLENTY of it's truck roots. There are plenty on here who loads theirs down regularly.
I have found the Expedition to be better in the snow, and adverse conditions, because of better weight distribution, and more weight over the rear than any of my previous 250's or 150's.
"Flex fuel"(By the way, I hate this term) is a partially complicated conversation. From the factory, it is WAY easier to make a NA motor Flex Fuel capable because the power variance, and fuel delivery variance are smaller. The capability and demand for Fuel delivery when going to full E85, on a Turbo motor is a whole other story. The Pump has to have a MUCH higher flow rate, than would EVER be needed with even E30. With proper tuning, the stock pump can handle full E85, but it is "turned down" a bit. It is faster than a 93 tune, especially as heat becomes a factor, but slower than E50. From a performance standpoint, our 2020 Limited Expedition Max is stock other than tuning. ZFG 93 Tune is good for a 5.04 second run to 60, and the E85 tune is good for 4.72 second run to 60. We have never tuned it to E50, because the wife doesn't want to mix. I run E85 most of the Summer, and 93 in the winter. Hope that clarifies a bit.