P&P Class Features in RP

[Kuroyukihime]

How are we to treat P&P class features that weren't implemented in NWN2's game engine in our roleplaying? For example:

Tongue of the Sun and Moon (Extraordinary): Monks of 17th level or higher can speak with any living creature. (This doesn't mean "give monks every language", it means "creatures that can't understand Common for whatever reason can still understand what this monk says".)

A Thousand Faces (Supernatural): Druids of 13th level or higher can change their appearance at will, while in their true form. This acts as a Disguise Self spell, with some key differences: it only affects the user's body, not their possessions, it is a supernatural effect, and thus cannot be dispelled (but an antimagic field would suppress it), and it is a real transformation, not an illusion. (Keep in mind that True Seeing would still see through it.)

Would making use of class features such as these be valid for RP?

[Passiflora]

No, unless a DM autorises you to do it in an overseen event.

[scriver]

The same goes for spells, doesn't it?

[Passiflora]

Yes.