I have a banjo catfish that came in as a hitchhiker on some plants. Have had him for about 6 months and have seen him maybe 4 times. All four of those times were when I was re-scaping my tank and "dug" him up. I cant help you with the feeding question, I have never seen mine eat. Just thought I'd let you know, unless you have a bare bottom tank, you may never see yours either, they burrow.
Blue