a while
well unless your having a baby tooth extracted there should be no other tooth that comes in.
couple hours.
1 or 2 months
well, it depends on the situation
about two to three months.
6 Hours
It should not take long, if you are having trouble see related questions answer
24 hours
Tooth decay is generally not cured. Usually it is removed along with part of the tooth. In this case the 'cure' is a filling that may take 20 minutes or a crown that make take 2 weeks.
its fine as long as it was a baby tooth. it will eventually sand down the sharp edges and fall out and he/she will be fine. if its an addult tooth take him/her to the vet to possibly get it pulled.
Not sure what you mean by damaged tooth. But a tooth that no longer has a nerve root will turn gray if not filled or capped. it can take from months to years depending on many factors, but it will turn if not treated properly.