I've only done the Bright Angel hike once, but it was this summer so it's still kind of fresh.
I believe my brother and I ( 16 & 18 ) did it in 2-3 hours, but we were jogging most of the way. We left around 4 or 5 in the morning to beat the oppressive heat of the summer. Most everyone made it down to Phantom Ranch by noon including a 70+ year old with two replaced hips, so it's very doable.
Water could be refilled halfway, so carry some salty snacks and 2 liters of water or more. Blisters are also a big problem, but we did it barefoot so no problems there! Once you reach the river the trail follows the river on sand. This is extremely hot as it heats up (by 9 or 10), so try to get there early and beat the scorching 120 degree temps in the summer.
We never came across mules, and I've heard that most mule trains head down starting around 2am so they're usually out of the way for the hike. If a train is coming through though they have right of way. No beta on the parking.
There's a creek running by Phantom Ranch - it'll be the most refreshing dip you've ever had.
Won't be of much use but I have a couple pictures of the canyon including a couple of the Bright Angel trail on the hike in: Views of the Grand Canyon
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