If you are talking about,pluging off your bottom drain and just using your skimmer only to run your pool,then you can buy a plug made of rubber or cork to fit inside the hole inside your bottom drain. Just make sure it is in secure. We do this every winter,when we close our pool,because our filter is below our pool. If we don't water will run back in to the pipes and could freeze and bust the underground pipes. We have been doing this since 1977. Good luck.
You can't
You have no choice but to replace the liner
If it is a vinyl liner pool you have to use a submersible pump. You can get a small one for right at $100.
Vermiculite
The experts at Advanced Pool Coatings have been installing fiberglass coatings over vinyl liner pools for over 30 years. You can read more at: http://www.advancedpoolcoatings.com.
YES.
no on paint! You will need to replace the liner.
Most main drains for vinyl liner pools have a threaded port inside of the drain itself. This threaded port is used to plumb in the main drain. The easiest way to fix this is to swim down to the main drain, remove the grate, which is held on with two screws, COME UP FOR AIR, then screw in a threaded 11/2 plug into the port. This will stop water from leaking if the leak is in the line itself and not in the drain.
With a Vinyl Liner you should not empty it OR take it down. It's very hard to get the liner back in place if you remove it. Vinyl shrinks as it ages so you also need the weight of the water to hold it in place. Movement of the liner could also cause older vinyl to crack. Think of an older cars dashboard! To winterize the pool you should lower the water just below the skimmer, plug the return line, drain the skimmer, pump, filter and plumbing and cover the pool with a winter cover.
No
The answer is no. Vinyl liner pools and the concrete deck around the pool are constructed with "concrete receptor coping". The concrete deck is poured into the receptor coping which at the very bottom has was is called a "bead receptor". The vinyl liner at the top has what we call a bead, used to install the liner into the bead receptor. Because there is, and can be, only one bead receptor, a second liner cannot be installed.
There are a number of ways you could remove stains from worms on a vinyl liner. You could use cleaners.