That is a beautiful tree that has been well cared for. It does well in cool, but not freezing temperatures. It is unusual that it has not lost more of the lower branches
. I see one that has lost some of its needles and can be pruned off.
It is not diseased and I am not sure why you suspect it is.
The only problem is height. The tallest stem is already at the ceiling and will only continue to grow taller and push against the ceiling. If you prune off the top growing tip of any stem, that stem will stop growing and may very slowly die back over the course of several years.
The bend is because it grows toward the light.
Don't even think about repotting it!