It seems fairly common for Celestrons produced in recent years to develop a milky appearance to the inside of the corrector over time; I assume it's due to outgassing from the grease they're using. If it gets bad enough after a few years it's easy to remove the corrector for cleaning, but it would be nicer if they used better quality grease in the first place.
I don't know what the snaking line is - scope lice perhaps
It doesn't look like mould.