I repotted my paph delenatii last week, there were more roots but the roots did look similar to what is in your picture (I can't tell the firmness of your roots from your images).
I cannot say what the insect was you described. I have been very fortunate to have had only a few mealy bugs and some fungus gnats.
Repotting every 6 months is bit much, IMO. Once a year is OK from what I have read.