My visualization is that the interment is on land in a nearby cemetery. But it depends on one's imagination.
Yes, the last notes of measure 4 should definitely not fade away, as that measure is in continuous crescendo. Thus, you must continue carefully "spending" that crescendo.
In the p section it's alright to give SOME increased emphasis to the LH descending octaves. The reason is that scale figures in compositions are important. In this case the scale happens to be chromatic. HOWEVER, the melody is still in the RH there, and remains supreme. So that additional LH emphasis on the octaves cannot compete with or drown out the RH--it has to be kept in proper proportion. The fact remains that the RH melody is foreground, that is, in the limelight, and the LH is background accompaniment. Thus, those descending octaves cannot ever dominate by being even louder than the RH melody. What gets most emphasized at any time in any piece is what holds the listener's greater musical interest. Melody predominates over accompaniment, although certain things can be reasonably etched in the accompaniment such as an accent, an inner line, a scale figure, a strategic harmony, shift of melody to the LH, an independent LH crescendo, etc.--but only within the bounds of musicality.
Following the subtle crescendo, the soft pedal needs to go back down in taking the final chord in the piece. The rinforzato accent there means to reinforce it, but again, only within the dynamic context. Except for that very short crescendo played non troppo (not too much), the dynamic of the third iteration is pp, and to that dynamic the ending must return. ppp is even more effective there if you can manage it. So that accent on the final chord is not punched. It's a very subtle, gentle firmness of touch to produce clarity, nothing more. It's like a soft tenuto.
The ritenuto in most editions actually begins on the third beat of measure 11 (not in measure 12) at the very same time as the crescendo. Together they produce a combined allargando or broadening effect. In the last chord of measure 11 you have a Cm first inversion chord, while in measure 12 there is a return to the tonic chord, as you point out.
I hope this helps.