Jerry, your elm will do much better off outdoors. Do it gradually, from indoors to a semi-shaded area to full sun.
Do not mist it anymore. Water drops on top of the leaves as a result of misting will act like magnifiers in the middle of the day when the sun is up above, and this little megnifiers will cause burns on the surface of the leaves. After a while the foliage will be full of brown and black "burned off" spots.
If you still want to mist the tree do it early in the morning only. That will allow enough for the water to evaporate before the sun is higher up on the sky and fries the leaves. Do not mist in the evening as the humidity will remain on the leaves and branches all night, and you will just calling for fungus problems.
Another common reason for elms loosing the leaves is root fungus. You mentioned seeing some mold when re-poting, so i think we are right on the money. Get some good fungicide from your garden center asap. Ortho has very good ones. Dilute it as per the instructions on the bottle, and mist and water thoroughly your tree with it. Make sure the soil is all soaked with the solution. Dont do it right before of after watering your tree (the water in the soil from a recent watering will dilute the fungicide even more and make it less effective, and watering the tree right after applying the fungicide will just wash it off). Repeat after a week. That should get rid of the problem.
Hope this may help your elm.
Gene