Yes, as bacteria/infection is most likely the culprit you want to remove that bacteria and dead tissue before a full blown absess occurs. With an abcess some will and some wont and it all depends on your dental professional.
Root canal surgery is done by an endodontist.
Yes they can, they did on me.
When it can't be stabilized
Yes.
Other types of roots include fibrous roots (found in grasses and other monocots), aerial roots (found in plants like orchids and ivy), and adventitious roots (developing from any part of the plant other than the radicle). Taproots, like those found in carrots and radishes, are another type of root system.
3 (the source is my dentist, he just referred me to get my root canal done on 15th)
you probly have a painless absess or need a root canal
what could have happened is that the root canal was not done properly, or the tooth was so damaged that the root canal did not work. In this event, the tooth may have to be pulled (its what happened to me about a week ago)
Yes, in Italy for sure.
there shouldn't be pain
Yes. I had a root canal done on one of mine when I was 10 or 11 and one on the other front tooth a couple years later, as the result of an accident.
It is possible to have more than one root canal treatment on a single tooth because some teeth do have two roots. The need for another root canal can occur within a few weeks of the original one or several years later