These are all the hints I've gotten. Last 2 pics about 821 cover are just a theory (based on the fire hint) made by a dude.
I think that Luffy is pulling a powerup that uses fire in a certain way (gear 5). His awakening is not about turning his surroundings into rubber but about converting his rubber into liquid rubber. This may even be related to the df the Gorousei are talking about if the GIF hint of the cat with the book "the art of military strategy" refers to it. Maybe Luffy is not the gomu gomu no mi but the nika nika no mi (oil).
No awakening or new fighting style hints
@MonsterKaido, this doesn't look good