Answer 1. There's an entire section for that: Advanced Roleplaying. Many people there pump out 3 to 6 paragraphs a post. I tend to go for either casual or advanced, and I personally usually do 2 to 5. My record is about 20 paragraphs, but I try to only do as much as is actually necessary. Word count shouldn't be a pissing contest. :lol

Answer 2. Drama is rare overall, but historical and low fantasy RPs often have massive debates about what it historically accurate, and sci-fi RPs sometimes have scientific "discussions" to decide what is plausible to keep it realistic.

Answer 3. I've never seen smut/sex RP, but I've heard of it happening occasionally. Overall, it seems to be rarely ever posted publicly: it's only done in PMs for the sake of site rules. It is a bannable offense, after-all.

Pro-tip: don't tell people you have Asperger's on the internet. Half won't believe you and will claim you just want attention, because they don't understand how the brain works. The other half will act like you're stupid or imply you need constant help, because they don't understand how the brain works. A few will treat you like Sheldon from Big Bang Theory, because they don't understand how comedy works and watch Big Bang Theory. RPG is a really accepting community and I don't expect you'll run into any of that here- most people will probably simply ignore it- but it's just better not to go advertising a mental aberration to strangers.