No. Curved shower rods have a unique crescent shape that keeps the water from getting on the floor. They also give you more physical space in the shower. Many hotels are using these shower curtain rods in their hotels.
As long as care is taken to insure that the shower liner remains inside the tub, there should be no water leakage.
Yes. Tub or shower water entering the wall through loose tiles or grout can run down the pipes, through the holes the pipes are going though, and into the unit below. It is more common for water to get into the unit below from leaking shower doors or poorly used tub/shower curtains that allow water to leak out the face of the tub/shower. It then enters the gap where the tub/shower meets the floor, then builds up on the sub-floor, and eventually into the unit below.
If it's a simple water leak your insurance company probably won't offer much help. a plumber will take care of the leak but then you'll need to get a contractor to patch up the water damage.
Possibly, but the supply lines should be in the wall. Even on a slab house, the water should come into the house at the water heater and then be in the walls. Possible heat vent leak? I'm assuming a slab house because if there was access underneath, you would be able to tell if there was a leak.
The shower may be leaking from: 1) A failure of the drain and associated piping itself (e.g., corrosion of the cast iron floor drain), 2) A failure of the shower pan, which is an ostensibly waterproof liner (may be metal or synthetic polymer) embedded in the tile floor (or comprising the plastic floor) which is mechanically connected to the drain; or 3) Leakage of water in the shower's surrounding area (walls, non-pan floor area, etc.) which is accumulating and dripping near the drain.
All showers need valves. They can be for the water supply, balancing the water and control of the shower. Without the valves, your shower will leak, causing damage to the surrounding areas.
If you have a new pressurised water system there is a possibility that the added water pressure could cause a leak.
Seats in the main valve body are leaking by, allowing water to go to the shower head.
A drain leak, a leaking shower pan, a leaking shower valve or piping, a leaking bezel or escutchions on the shower valve, bad or missing grout, bad caulking in the corners of the wall, a leaking shower door, water spilled on the floor, or, a drain pipe leak. any one or combination of the listed problems can do it. Look things over take care of what you can see wrong before making a hole in the ceiling. If you think you have fixed the leak repaint the stained area but prime 1st with Kilz or Binz to cover the stain or it will reappear through the paint even if the leak has stopped. If the leak hasn't stopped from taking care of the things you could see then open up a hole to see where it is coming from.
I don't know if you are looking for any specific person, but if your question is why should you leave the shower curtain on the inside of the tub, the answer is simple. If you leave the shower curtain on the outside of the tub and take a shower, the water that runs down the curtain will be on the floor outside of the tub and you will have a mess to clean up. But if the curtain is on the inside of the tub, the water just runs out of the tub and thee is no mess to clean up. Conrad Hilton said it.
the shower and bath water comes from two different places so their is two different pipes. Get the shower pipe checked out by a plummer and they cause fix the pipe.
When you pull the stem up, it diverts the water from the tub spout to the shower head. Somewhere between the valve connection and shower head arm, you have a leak. The easiest part to check would be the arm that comes out of the wall that you screw the shower head on to. It is normally screwed in to a "shower Ell" and that connection and or pipe is easy to crack if someone pulls on the shower head. Pull the escutcheon plate towards the shower head and try to see into the hole and look for water at the connection. It would only leak when you are using the shower. If it is another connection or the riser pipe itself, you'll have to access it through the wall, hopefully from a room on the opposite side of the wall. Good Luck