Yes
No
YES.
Vinyl Liner
Pool with a vinyl liner.
Well first of all there is no such thing as a fiberglass pool. You can have fiberglass walls instead of steel but your pool is still vinyl because you need a liner. These are the usual combinations of inground pools. Sand floor, steel walls, vinyl liner Sand floor, fiberglass walls, vinyl liner Vermiculite floor, steel walls, vinyl liner Vermiculite floor, fiberglass walls, vinyl liner Concrete floor, steel walls, vinyl liner Concrete floor, fiberglass walls, vinyl liner Concrete floor, concrete walls, no liner Concrete pools have to be painted with epoxy paint or if you want tile installed then usually you plaster over the concrete. Now a days 3 and 4 are the most common inground installs. 1 and 2 are usually pools that are 30 + years old although you can still have them done that way. In South Alabama the cost of a 20 *40 vinyl pool will cost around 18 to 22 thousand
Very expensive
High concentrations of chlorine can and will destroy a vinyl liner.
Bleach marks are from chemicals comming into contact with the liner.. Never add dry chemicals to the pool, completely dissolve all chemicals in water before adding to pool... That information should have been given to you when the liner was installed..
You can't
28 or 30 mil
No. Replace the liner.
To fix a detached vinyl liner from its spot on an above ground pool, the water will have to be drained from the pool. Then, a marine patch can be placed on the area to re-attach the vinyl to the place where it came apart. Allow this to dry thoroughly before refilling the pool.