One exercise I would include (if possible for you) would be a lower back movement, using a hyperextension bench or hyperextension machine. Depending on the bend of the knees and if you can handle it. Adding a leg curl exercise if you can . Lower back and hams actually can help with weaker legs/hip becoming more stable. Not a cure all by any means, but just a suggestion. Just wonder if you use a leg brace, built up shoe or cane when moving about?
Probably doing all your workouts sitting, reclining or laying flat. So your not limited to most exercises. With 6 years of experience working around any leg problem, you know your body better than anyone else ever will.
The program you listed looks pretty solid, if wanting to work certain body parts once a week. Shoulders & trap can be kind of cool. Your not the only BB'er who has ever used that combo before, with good results. Ever decide to work an area twice a week, than you might want to consider something like this.
Mon.....Chest, delts (lateral head focus, the anterior delts gets hit hard from most chest work) and triceps.
Wed.....Back, traps and biceps
Fri.....repeat Mon workout
The following Mon do the: Back, traps & biceps
Wed....Chest, delts & biceps
Fri.....again the Mon Back, traps & biceps
Alternate again the next Mon each start of a new week
Actually there are dozens of excellent ways and programs to use each week for upper body only. Looking at most guy's who BB, they never hit quads or calves very hard anyway.
Good Luck
Side Bar: friend of mine, in a wheel chain, main exercises were rope climbing , chins and dips. Started all this at the Navel hospital in San Diego, where he went for rehab after Gulf War I. His chest, shoulders, arms and back are huge now. To be honest he looks top heavy in that wheelchair of his, like he's going to tip over at any moment..
