First couple I can think of.
All class information is here: https://7daystodie.com/forums/…967&viewfull=1#post808967
And in-case you missed it right at the top....
Books must be on your toolbelt, and in your hand in order to be read. You must use left click to do so. The read shortcut does not work due to something TFP disabled.
Perks saying "disabled by status effect" when you have no status effects happen because you managed to unlock the perk before meeting the level requirements. This can be from purchasing a perk and then gaining a level in it via class, or from reading a book before your level is high enough.