Yes, what you see in the picture is what you get.
yes with some modifications including cutting the door to the proper heigth.
These are designed for 1-3/8" interior doors. The thicker door would have a very tight clearance.
Door is not included.
If this is a low use door, then it should be okay. If it will get a lot of use, I would recommend the 1500 Commercial Grade Pocket Door Frame. May not be available at HD but other places have it. Just google it.
It's designed to match 2x4 studs. It will work if you don't mind having a wall with two thicknesses. Or you could fir out your 2x3 wall to match it. My suggestions is that you spend a little more money and go with Johnson. You'll never miss the few extra dollars. Pocket door problems are not an easy fix.
The instructions are generally with the door. If they are missing there is a link that has some instructions here on .com. They are not complete with RO dimensions needed though. The store can copy you instructions or Orepac can provide info. The RO needed is 2 times the width of the door being used plus 1-3/4" and the height is 84-1/2"
Yes it can. At the top of the door where the hardware is attached, there should be small levers that you can flip open with a screwdriver and release the hardware from the rollers. I attached a photo of the hardware from the homedepot website. Yoiu can see the brass levers on the zinc plated hardware that attaches to the top of the door. Those levers lock and unlock from the rollers. unlock the levers and the door will seperate from the rollers and y ou can take it out. You might need help with holding the door while you flip open the levers. I hope this helps.
I had installed in both pocket door frames a solid core pine door , i will handle most solid core doors with out an issue, glides are well made.
I don't know the answer to the weight question but I can tell you that we hung a pretty heavy door that had 15 windows in it. 3 across, 5 down. It was quite heavy and the door works fine.