Just one sink, or the whole house?
Drain, Waste and Vent System. It is all of the Drain and Waste piping and their associated vent piping
Storm drainage piping.
Vent piping is a pipe that runs outside and is connected to the drain line of your home. this helps the water in the drain to move to your septic/sewer.
Yes, be sure to pipe floor drain line properly into water closet piping.
drain
drain
You cant, you have to remove the section of piping and install a new section of piping.
yes.
Drain cleaner pollutes the environment after it is poured down the drain. You should use green cleaners.
Shower drain goes into a trap under shower. Continue piping from trap to drain line.
You don't, a roof drain is nothing more then a conductor that allows water to enter the storm water piping and then the piping leads to a place of disposal.
Basement, if any, will oft times have PVC piping used for drain lines in it, if codes allow PVC piping.