Where do you live? up north phals can tolerate a little direct light. In south Florida any sun will burn it. They do like bright shade. Cut the spike to the base...

I don't cut spikes until they are brown and dried for 2 reasons. First, some phals will have dormant buds that will produce flowers or a baby plant in a few weeks. Second, I feel cutting while green can open the plant to infections. Waiting until it's brown and dry gives the plant a change to close the pathway. This is just my feeling, not based on anything else.

As for the window, it is probably okay but not all east windows are the same.

First, some phals will have dormant buds that will produce flowers or a baby plant in a few weeks.

This is true, but both of these actions drain energy from the plant that can be used for growing new leaves and/or roots. Cutting the spike helps to ensure that during the growing season energy is spent on growing new leaves or roots.

You don't have to cut the spikes off though-it's the grower's choice. I've seen plenty of people who cut the spikes and plenty of people who don't.

I feel cutting while green can open the plant to infections. Waiting until it's brown and dry gives the plant a change to close the pathway.

Also true, but you could always spray some peroxide and dab some cinnamon on the cut wound to prevent infection. Cutting with sterilized scissors is also important. I've never used peroxide or cinnamon on the spikes that I've cut-I've only used a pair of sterilized scissors-and I've never gotten any infection. :P

I'm not saying that the chance of an infection happening is zero, but you can certainly lower the risks of an infection significantly.

I cut my phal's bloom spikes down to just above the highest node, and it bloomed again. I live in Philadelphia and mine sits in a southwest bay window