Phal New owner : Am I doing this right?

[mothinuk]

So I received a Phal about 2 weeks ago as a present. I have never owned an orchid before, but am very interested in learning the proper way to care for it. It is a dual stem Phal with about 8 flowers on both, and 3 unopened buds on both stems as well. Since having it, 2 or 3 buds have opened nicely. There is also a grabber/root that is growing (silver tipped) I have a wooden peg in it, to test when I need to water it. It has a moss on the top for the plant, that half is green and half is brown (looks dead). I try and keep the moss moist, and I do this without watering the plant. I soaked the plant in water for about 15 minutes the other morning, and then drained the extra water. I realized that I have very hard water, so I went out and bought some bottled water for the next time I soak it. I have the plant actually away from the window at the moment, as it is drafty, and typically overcast outside (although I do open the curtains to let some real light in. I have a 100000lux lamp on the desk that is beside the Phal, but not directly shining on it. I did the shadow test and it does not appear to be too much light.

Hopefully I am doing things right so far.

I am unfortunately in a drafty area as I said. I have a radiator that I can manually turn on for about 2 hours, getting the room toasty, but otherwise it shuts off and the room gets to about 50- 55F. Hopefully it will get a bit warmer soon. The radiator dries the room out, so I have put the plant (it has a clear plastic pot with holes inside a glass pot) in a tray, and have a washcloth damp in the tray. I was wondering if I should take it into the bathroom with me for showers (sounds extremely odd to say that)? So it can get some humidity? The bathroom is so small and gets no natural light, that I didn't think it would be the best permanent place for the Phal, but please correct me if I am wrong.

Today one of the first blooms (bloomed prior to me having it) has wilted. The stem has shriveled, and the flower is wilted, though appears to be still in good color as the rest. And secondly I noticed that one of the leaves near the bottom leaf has turned a bit yellow in color and has some indentations in the middle of the leaf. There are 7 total leaves, 4 on one side, 3 on the other. This leaf is in between a smaller one (lower) and a larger one (upper). I don't know if this means I am doing something incorrectly or if these are the natural deaths of the plant parts.

Also when do I cut the dying flower back? I have heard that they can sometime come back, although I am not sure what circumstances they do that. Also if the leaf is dying, do I need to cut that back ? Or let it naturally fall off?

Many thanks