I was taught by a chinese restaurant chef his technique for how to cook chinese rice in a normal pot on the stove at home. The technique consists of (after washing away most of the starch) starting out by submerging the rice under an extra couple of centimeters of water (you use your hand/knuckles to measure, it's not super precise) and high-heat boil uncovered till the water level drops to even with the surface of the rice. Now cover and put heat down very low and let the rest of the water absorb while you make your stir fry. Before serving, turn all the rice over a time or two with a paddle and let it resettle uncovered, this helps the rice dry a little and be less sticky, but keeps it cluster-chop-stick-able.

I explained all that to say, I adapted that technique for a microwave and it worked great right away. Microwaves vary a lot in power and timing, so I can't really give a how-many-minutes recipe, but the technique just works.

From my experience microwave heats up water so fast it doesn't matter. I've used coldest and hottest tap settings and as long as water level is right it works fine, provided you wait long enough after cooking for the rice to absorb the water. Usually I just wait 10 minutes. If it's still a little wet from cold water, I'll fluff the rice, stick the lid back on and wait a few more minutes (assuming this is using a microwave rice cooker).

The water is coming from the reverse osmosis tank, not the faucet. Thus it will be at room temperature.

There are different ways of doing it, but when I microwave rice I boil the water in a kettle first