On the 744 there are actually extinguishant systems for the bin.
As to Oxy Masks, yes they are required in the toilet.
Dani is right, it doesn't have to be serviceable, but if that is the case then the toilet would be locked unservicable PREFLIGHT. So, masks are required in a serviceable toilet.
We could just design the aircraft without masks in the toilets, and then just have them unservicable permanantly
. Short flights only haha.
As to the Ash Trays in the toilet doors... there are still airlines that allow smoking, so it would be a general design and certification issue. In fact, our MEL requires that they are all serviceable or no dispatch! (Even as a non-smoking airline).