I have a basket of epidendrums grown from cuttings pretty much. First of all, those roots are way rotted. Cut the brown mushy stuff off and lay the little thing across the top of a pot, using the remaining healthy p-bulb laying across the top. The little one eventually will suck the p-bulb dry, as it grows larger and grows roots of it's own. It's going to be awhile. Knock off the serious watering thing....these like to be in potting soil mixed with orchid bark....imagine it growing atop the forest junk just above the real dirt. It's a humousy mixture with a little real dirt mixed in. Keep it moist but never ever soggy. Until the little thing sprouts roots I'd stick to misting it and let the dirt mixture run a little on the dry side. The smaller the growth, the smaller the pot. Don't let it worry you, these grow well and fast. It can take as much sun as you give it. But that is long about springtime...while it's so small it can't handle full sun. Some direct sun in the mornings is okay, but unless you have a greenhouse, keep it shaded for the first few months. About 2500 footcandles...phalaenopsis level and moisture levels at first. Once it grows a couple growths and gets bigger you can really ramp up the sunlight.
Good Luck
Connie