Phals: root rot, dormancy, and dying leaf?

[ceropegia]

Hello all, I'm new to the forum.

I've had my 4" phal for 2 years now and it hasn't bloomed since I got it. I purchased it in the summer right after it had bloomed (a sale orchid at lowe's) so I didn't expect it to bloom for awhile. It didn't grow any new leaves until last summer, when it put out 1 long skinny leaf and a smaller, shorter leaf. It hasn't shown any signs of blooming since I got it. Could it be dormant, or is there another problem?

All 3 of my phals (a 4" and 2 3" "minis" of unknown color) seem to have a touch of root rot, as you can see in the photos. I repotted the two minis recently and one has grown a small spike, despite the fact that some of its roots are shrivelled and one of the leaves is turning yellow.

Should I cut the shrivelled roots off? I've done it once before, but there was a thick green vein inside and I was afraid I was cutting into a living root even though it looked dead on the outside. Any advice?

Also, is it normal for the leaves to turn yellow while the flower is starting to spike? Ive heard some people say it is, while others say it isn't.

Sorry for all the questions! I've been wondering about them for awhile, so I decided to join the forum and ask.

Oh, and here's some info as to how I'm growing them:

-all 3 are in an east-facing window
-the 4" is in a sphagnum/bark mix, the other 2 are in sphagnum
-the window gets cool at night and the room is warm during the day
-all 3 get misted each morning and watered when the moss appears stiff and dry

Photos:
#1: "dormant" 4" phal
#2&#3: "mini" phal with root rot, spike, and yellow leaf