With Drokk I originally wanted to make him a jaette. I never got around
to it, though. However, I am curious what the immortals think of players
role-playing non-player races.

Let us take the example jaette (as described in the areas around Udgaard)
vs fire giant (the player race). There seem to be a lot of similarities
between the two races and there is some in game jaette culture so it would
be possible to role-play a jaette.

Is the best approach to have a role which describes how the fire giant
in question was raised by jaettes and thus adopting their culture, but
still leave no doubt as to that the player is a fire giant.
Or is it alright to say (in the description for instance) that the player
is a jaette, despite the fact that everybody looking at the player will get
the impression that he is a fire giant.

Another example could be wood-elf vs. dryad for instance.

Note that this is a question asked out of general curiosity. I, personally,
have enough trouble playing the non-humans that exists already.