Questions regarding dendrobium kingianum

[vbng]

Hello everyone,

Please help me out here. I have 6 questions below regarding my newly bought dendrobium kingianum (from Australia) (image 1) and not sure if you can explain the root case and what should I do to help my plant. Thank you.

1) The white roots are all dried out underneath and so I cut them off leaving only 1 inch of roots behind but the roots are thin and brown like straw. (images 2)

2) There are some roots wrapping around the stems and not sure if they are still alive. (image 3)

3) There are some leaves turning yellow. (images 4 & 5)

4) There's a black dot sort of like burnt dot in one of the leaves. (image 6)

5) There's a leave with split ends. (image 7)

6) There are many tiny black dots on the stems and not sure if they are fungus. (images 8 & 9)



Thank you,
Vicky