None of my orchids will flower and one is dying.

[ambersartain]

Hi. I have an Epi. Mabel Kanda 'Miyao' x Epi. Randianum, a Blc. Williette Wong 'The Best' and a generic dendrobium from Wal-Mart. And also a den. from Kroger that said Burana Pink on it. That's the dying one. The other three are mine, and they look pretty healthy except for last summer's sunburn. It's just that they will not bloom. I'm growing my three in s/h culture, and I had just repotted them, and I know it's backwards, but after I repotted them, they've all started to grow new growths. I used rooting hormone when I repotted. I don't know if that has anything to do with it. They seem okay, but like most people who grow orchids do, I want them to do better than okay, and since I've never seen two of them bloom, I'd like to see that too. They had been getting water most of the time and getting way too much food I found out when I did feed them. Then came the repotting and the rooting hormone. Now I've started giving them a tsp of MSU fertilizer/gallon of water. I've only done that once so far. Light is probably a problem and so is humidity. I keep them under shop light with plant bulbs in it. It's all I can afford right now. They're by a window, but it is pretty dim. Also, the air in the house is usually pretty dry. I don't really know a very good way to bring the humidity up and don't want to mess things up in the house if I do it too much.
Then, there's my sisters dend. which I offered to take care of, and boy did I. It was in some kind of palm stuff and it looked like the roots were getting too wet so I decided to repot it and I'm really bad at wanting things perfectly clean and so I tried to get all the palm stuff off and when I did, so came most of the roots. I have it potted in fresh fir bark and a clay orchid pot now. I've been giving it rooting hormone and last time I watered I went ahead and fed it with the rest of them thinking it might help. And the dry air has to be killing it too. Esp. with no roots. And the leaves keep turning yellow and falling off. Is there any way to save it?