A: Yes, but not the 6 1/2 one.
A: Yes, a 4" roller will easily fit within this tray. The width of the interior of the tray is about 5". I find these trays very useful. One tip - I use hot melt glue to fasten the 4 corners of the bottom of the tray to a small piece of wood (usually plywood). that provides rigidity to the tray even when full of paint. And it's easier to carry (by the wood).
A: Yes. It’s perfect for 4-inch rollers and also small and medium-sized brushes.
A: Will this tray hook to ladders
A: No. The interior width is about 5".
A: No, 6" mini roller don't fit on this tray.
A: No. You need a slightly larger pan which they have.