I can't answer the prostration question, both because prostration is conceptually alien to me as a western Christian, and because I can only recall that particular event vaguely. I'd guess that it was a show of Christian compassion and magnanimity.
I prefer portraits, but only of women; there's nothing coarse or vulgar about this, it's just that, in a world where femininity seems to have disappeared, perhaps my only means of experiencing it is the vicarious one of looking at pictures of women from times when they still were feminine.
Smerdyakov was both a hilarious and a tragic character. I love how in at least one translation later than the Garnett one, his language is rendered into that of the uneducated English dialect of East London and northern England (the use of third person verbal conjugations in the first, double negatives as negatives, etc.) this makes his amusingly haughty cultural and intellectual pretensions seem all the more ridiculous - and therefore funny.
Do you wear a mask to bed?