Yes Freddy you can! It would be a bit of work as you would have to use a stripper to help remove the paint and do some sanding to get all of the paint off before you stain and finish with a poly. It can be a big messy job that takes a while depending on how many layers of paint you have to strip.
Only if you completely strip them and sand down to the original wood! Enjoy the journey.........
Do you know what kind of wood is under the paint? Unless the cabinets were originally stained, they could be just plywood or perhaps MDF. If they are real wood, you are in for a ton of sanding. I'm not sure you're going to find all the effort worth it.
Yes but it will entail stripping and sanding.