1.  What do you consider to be the biggest challenges in writing your favorite genre?
My favorite genre is drama, specifically medical drama.  I think one of the biggest challenges is doing enough research to write it realistically, yet writing it in a way that still sounds like a story, not a medical textbook.  Another challenge is getting the emotions right.  You want the characters' feelings and emotional reactions to seem genuine and believable, not over-the-top and melodramatic.  It's easy to get cheesy in this genre. (Hey, that rhymed LOL.)  
2.  Are there any genres you enjoy reading, but have a hard time writing?  What are they, and why?
I love reading suspenseful mysteries and thrillers, but I have a hard time writing in that genre.  My villains are too cliched and cheesy, and my plots are either too predictable or twist their way right into plot holes I have a hard time digging myself out of.  I admire people who can write stories that are genuinely suspenseful and keep you guessing, while still maintaining a certain plausibility. 
3.  What is your danger zone when it comes to writing?
As I mentioned in the first question, it's easy to get cheesy in the genres I like to write, so I think that would be my danger zone.  I love writing tearjerkers, but I have to stop and think, "Is this line or scene I'm about to write going to make people cry or just roll their eyes?"  I'm always walking a fine line between writing something poignant and heartbreaking and writing something sappy and cheesy.