Webs in soil - cryptomeria

Hi,
I wrote about this tree before, it was in a poor state.
I checked the roots as it was recommended and I found that where the pot drain-holes are, there're actually holes in the soil and seems like a spider made it it's home, as its full of webs.... Also,, the side of the soil is white.... looks like mold to me.

I would say that the roots are quite packed - but I would welcome some advice

Thoughts? Taking into account that the tree is weak just now, do I repot it or fill the holes with more soil and let it be?

Thanks!

the white are beneficial fungi, myccoriza.
The soil probably is on the wet side. But I do not know the species. Soil washes out through drainage holes if not properly covered of very fine grained.

Thanks Leatherback. I had no idea!

No need to worry about the webs then!

Do you think this is root-bound or can it stay in the same pot for another while?