So I was mulling this over in IRC while people were chatting away. EFU used to have generic perks that any class could take, but they had mechanical advantages and disadvantages to them so didn't quite work out well.
But how about perks that have no mechanical effect, perks with just fun effects that may have some RP effects but are not even necessary to take? The best part is that they wouldn't actually require much scripting other than the dialogue menu to select one.
Some examples:
Collared: The old collared prelude might be a fitting option
Chosen Friend: Through some means of offering tribute and Machine destruction you've managed to become marked as friend to the Chosen (still hostile ambiently), but may have effects in certain RP situations when dealing with Chosen or with Spellguard NPCs.
Machine Enthusiast: You may not know much about animatron technology, but you are a fan of the Machine and often speak excitedly with Scrappers, Auxiliary and Spellguard....granting you greater access to the Machine and sometimes more favorable reactions with said people.
Workmill Revolutionary: You are a survivor of the Workmill Revolution, granting you more favorable reactions from some people, and far less favorable reactions from others.
Bloody Mess: Killing blows cause enemies to die in horrific ways.
Not really my forte when I do scripting for NWN but its generic DB calls can be used to assign integers to characters that can be called on login, then you can use something like a conversation dialogue to flag these integers on characters initially, and use those saveable integers in script checks for different alternatives when the script runs. So it should be easy enough to do, anyway, provided someone has the time to do it and find every obscure reference in the module that would relate to that perk and insert the alternative course If statements.