Usually the foliage will tell you if you have root issues. Some plants yellow or brown, others defoliate, many do both. The root rot issue, as Dorie mentioned, usually arises as a result of compacted soils or those that are just too water retentive. Sometimes it's the growers fault, & sometimes the soil is simply inadequate for use in containers, making it extremely difficult to grow in. Aside from your foliage telling you roots are rotted, your eyes and nose are helpful tools, too. Lift the plant from the pot & look for mushy roots, usually accompanied by equally musher soil. They'll be brown or black and break easily. They should always be pruned back to healthy tissue before returning the plant to the pot. If you smell the roots & they don't have a healthy, earthy scent, smelling acrid or sour instead, you know there are issues (unless you are smelling serissa roots, in which case you'll think you are in an outhouse. Worst plant part I ever smelled.). ;o) Al

10 foot from the house wouldn't be too bad if you keep it from getting too large. As for the retaining wall the roots don't seem to be too much of a problem depending on what type wall. Have you checked with your extension agent or local Master Gardner or even a GOOD Local Nursery? You can take pictures not the plant with you and let them help with your problem. You could in the mean time spray it with milk and water in about 5 parts water, and 1 part milk. This does in some cases kill some molds but not all. But if it is a mold or what ever you need to get it under control as soon as possible.

Replant after removing the rot especially if the bulb looks good.

I found an absolutely beautiful Jade in a dumpster when I was tossing my trash. I pulled it out and after trimming a bit it was absolutely fantastic. I proceeded to over water it and practically kill it. It got so bad that I thought it was a goner...and then I did the unthinkable. I cut off the entire matted and ruined root ball. The whole thing. I let it air a few days and stuck it in an awful mixture of street dirt. 6-months later, it is making a huge comeback. I barely water it now and give it a shower every six weeks or so to blow away any mites or whatever crawlies happen on it. It is doing fine. I happened on another specimen with an 8-inch trunk and I broke it up to make about 5 new plants with 4-inch trunks (the 8-inch was rotting). I'm hoping to get at least 3 of those rooted using the same method. Re-rooting a 4-inch trunk gave me some confidence with Jades. They seem to be really resilient if you sorta be a little mean to them ;-)