No. You have to purchase your own.
This particular model is for walls. It will not work on the floor since the doors will scrape the floor. You will need to purchase the base cabinet for the floor. Base cabinets have a toe kick so the doors are off the ground.
Yes, they come assembled. However, you'll need to insert the provided shelving pegs and insert the 2 provided shelves. You'll also need to drill holes in the doors to install any knobs you might want.
Two nicely finished shelves are provided for each cabinet. In the packaging, one shelf will be on top of the cabinet, and another under the bottom. Metal shelving pegs are also included.
Take the doors in and have them paint match it.
You are more than able to stack them, but stacking 2 wall cabinets does not make a pantry. Understand that a pantry cabinet is base depth (24") and wall cabinets are only 12" deep. So, you will be left with a 12" cavity behind the base if you are butting them up to existing base cabinets. Or they will be recessed 12" behind existing base cabinets. Either way, it's not an ideal look. If you are simply stacking these separately from the rest of the kitchen then you will be fine. Just realize you are still not obtaining a pantry as they are only half the depth of a pantry. I install cabinets for a living.
They are finished white. I would not paint them. I would recommend an unfinished cabinet instead.
I would not put more than 20-30 lbs in this cabinet. Thats a good amount
No,they are open across.