Can I revegetate plant that is chopped to the base?

Yes, lower branches have immature flowers. It is a good idea to re-veg. I have done this but I found the result to be bad. Plant will have thin branches, grow slow, and produce less. I found better use of energy and space. If you really get an excellent phenotype, it is a good idea to re-veg it. Then take the lower branches to make clones. After this, same phenotypes can be grow. Clones can be taken during pruning. Cycle can be repeat until you are bored with the strain.

maybe... i've had a new growth tip develop out of a stump before. this plant was outside and i simply didn't do anything with it after harvest. A week or so later, i looked and it had a brand new growth tip of 2+nodes popping out of the center of the chopped stem - not only that, it was an autoflower, which would only hurt the chances i'd assume, lol. I couldn't tell you how often it will happen. But it definitely does happen. Give it enough light (hours per day), but you obviously don't need 20-40DLI etc until someting sprouts. ambient light 15+ hours is probable fine until you see a nub growing. So, you don't have to waste a lot of watts or supplement a short-day sun cycle too much. I wouldn't over water, but keep some moisture in the substrate, obviously. don't count on this.. but if it's a bonus that you can make use of, it won't take much effort.

No, cannabis is an annual plant that has one life cycle........sprout, veg, flower, die. Any weird growths you get second time around will be mutated and end up being a waste of time and effort.........and yes, I am talking from experience.

Sometimes you can make small cuts into the trunk and encourage new growth, hormones help. but its rare for it to do that on its own or with help. My one plant has a mini sprout/shoot just below the main cut and it could re veg. Would take a long time but I would take clones on that new growth and let the main root stalk die. also only works for photoperiods not autoflowers

The more foliage you leave behind the more chance you have.

I would say No. no brach, no leaves left . Plus too big open wound, people plan upfront such things and harvest in certain way.

Typically if you plan to reveg a plant you need to leave some branches and leaves in order to get it going again. If you just have a stump I doubt it will reveg. You could give it a try though. It will either do something or nothing.