I'd do a pan-drop with filter change.
We did a pan-drop on a '97 F-150 (4.6l, same trans.) about 10 years ago is about the same thing, except the '97 had only 50,000 miles, so I guess that makes me an aspiring expert.
Is a pan-drop with filter change what you're planning, or something more?
Our fluid was dirty but 'acceptable'.
I don't think changing out "half the fluid" (the result of most pan-drops) would harm any operating transmission.
We also did a 2005 Explorer (with your mileage) that day. That old fluid looked the same. We were glad to see what was being run.
Neither vehicle was damaged.
Q1: Does anyone know if your torque converter has a drain plug? Remember to rotate the engine to find it.
Q2: MerconV, right?
On several occasions I've had to look for MerconV.
Even though it's a popular fluid, there mightn't be enough do-it-yourselfers to see it on parts shop shelves consistently.
The last time I bought some, it was a 6-pack of Valvoline brand MerconV for a great price on Amazon.