Ah, I remember this thread. Well, hopefully I'm not taken as the spokesperson for the Grand Master of Negativity this time, eh?...

A break in general is always good. Clear your head, reconsider things, come up with plots and characters that may be intriguing to return with. Not just any old plot, craft something, have some plans and plot bunnies to go with in the event of your return, and before actually coming back, give a look at the threads that are ongoing.
 - Roleplays stalling out of the blue is fairly normal regardless of the quality, methinks. You need someone special to get proper dedication, and eventually, the roleplay [i]will[/i] end, and you will be very lucky to actually finish a plot. My compensation is to put unfinished plots and characters into my canon, so that everything I achieve in roleplay will continue one way or another.
 - ¯\_(ツ)_/¯ Personal tastes may vary, I'm pretty sure superheros and smut are the cool shit right now if you're reaching for a broad audience, and others, who knows.
 - Couldn't speak for that without context.
 - It certainly does with me. Still, it shouldn't be that alone, as there are people who like such themes.

Breaks are good. Unless you're ripping out current roleplays, there is no loss to you taking time to clear your head/reconsider/whatever. Downright necessary to do at times.