Hi,
the first dream about the looping train tracks...the only things that now comes to my mind is that maybe it´s about a feeling like: ´life is playing with me...´
The dream about the prostetic legs and laying in the bottom bunk of a bunk bed:
Legs can symbolize how one ´stands in life´...about foundation, ones own standards and values about life.
Prosthetic can go 2 ways. On one hand prosthetics legs are something good because when one has amputated legs one can then walk again. But i tend to lean more towards the other way: prosthetic legs...replaced legs...could then refer to not living according to ones own standards and values. Looking at life through other peoples eyes...being (to much) influenced by other peoples opinions and such.
This seems to be explained as well by the laying in the bottom bunk bed. When i look back at the time when i was a kid and could sleep in a bunk bed and there were other kids involved...the upper bunk bed almost always seemed to be taken by the one with the loudest voice...the most popular one...the one who always was standing in front of others (if you know what i mean). What also comes to mind right now is that this maybe can even taken almost literally: laying in the bottom bunk bed...laying to rest...resting under someone else...´resting in´...
But this last one can also make it more positive again. Gives me yet again another look at it. Why the prosthetic legs? Maybe after much/always having had to fight. The prosthetic legs then can stand for resting in sort of a new situation. A situation with less fighting (about standards, values, opinions, for oneself). I think it might be about this last meaning, because in your dream you were encouraging him and complimenting him about how he seem to have overcome his disability.
Funny part....´he played bassoon´....i am dutch and the dutch word for bassoon is ´fagot´....i looked up fagot...hmmm....´he played fagot´...
Okay, enough...