Is it necessary to network enable both the parent and child theme for multisite installations?

A little late to the party, came across this question looking for the same answer myself – to answer your first question, I’ve done a brief test locally and it seems that the parent theme can be network disabled. I have three sites running, with three child themes network enabled where the parent theme is not and they’re all still standing.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)