Does the cooking time, adding more water and using high quality and expensive rice help to produce soft and non-stick rice?

This is what I do for cooking ONE cup rice:

1. Soak one cup rice in one and a half cup water for 20 minutes. This should be done after rinsing the rice properly since, the water used for soaking is NOT to be thrown away.
2. After 20 minutes put the vessel with the existing water on the gas stove (with a loose lid on) on a high heat.
   When the water reaches the boiling point (indicator: water starts to pour out of the top of the vessel), reduce the gas to a minimum.
3. After 4-5 minutes check whether the rice is done by taking the lid off sightly. Keep it on the minimum gas till the water bubbles on the top of the rice vanish completely.
4. Switch off the gas.
5. Let the rice vessel (with the lid on) be on that switched off gas for 15 minutes. The inherent heat of the gas helps in setting the rice properly and reduces the chances of the rice getting stuck at the bottom.

Also, using a thick bottomed vessel for cooking rice is a must. In a thin bottomed vessel, the food is more likely to get burnt if less water is used.

I'm sure Anisha's method works quite well for cooking rice in a pot. However, your question was specifically in regard to a rice cooker. So:

The answer to your problem (hard, gummy rice at the bottom of the pot) can be simple and inexpensive:

1. Use the rice cooker's standard time for white rice
2. You don't need fancy rice, but don't use cheapest-you-can-find either.
3. Rinse and drain the rice twice.
4. Then add an equal amount of water as the amount of rice in the cooker (i.e. 1 cup for 1 cup)

Reasons for the above:

1. I've never seen a rice cooker whose standard time for white rice was an hour. Are you sure you're using it right? It should be more like 20-30 minutes.
2. Really cheap rice tends to have a lot of broken and abraded grains which release their starch and turn to a gummy mush on the bottom of the pot.
3. In the bag, rice will have a lot of "dust" from processing. This is actually loose starch; if you don't rinse it off, it makes the rice at least sticky and at worst gummy.
4. Rice cookers require very little water for their rice since it's all absorbed. The amount of water you are using is too much even for rice cooked in an open pot.

For me, the whole point of a rice cooker is that it's easy and forgiving to use. It probably helps that we have rice almost every day, so we get lots of practice.

As others have mentioned, you have to rince your rice - for white rice I rinse it at least twice, more if I don't think the water is clear enough. Additional rinsing does make the rice less sticky, but it takes longer.

For adding water, I'm a bit less accurate than the other people who've answered. We rarely make "a cup of rice," we just pour in as thick a layer in the cooker as we think we'll need. If we want leftover to fry the next day or if we have a dish with a lot of sauce, we'll do more. "A small amount" is a layer about a cm deep in the cooker, a "larger amount" is a bit more than 2 cm, and "a lot" is probably 4 or 5 cm deep. After rinsing and draining most of the rinse water, fill the cooker until the water is a bit less than twice as deep as the rice. i.e. if you put in a cm of rice, the water should be a 2cm deep. Once you get to about an inch of rice, the water can be a bit less, so not quite 2 inches.

For brown rice, I put in about an extra cm of water.

If it were me, and my rice cooker didn't just work, I'd assume it was busted and get a new one. We have one that just has a single button that you push down to start the cooking cycle, and it takes about 1/2 hour to cook an inch of white rice. We also have a newer cooker than has both a Normal and a Fast setting, the Fast setting would take about 20 minutes to do the same amount.