Would you wear a pencil dress at work ?

totally nice...not formal (b/c it's not a suit) but office-like....pencil skirt reminds me of charleotte at SATC...she had many pencil dress while she's at the gallery...and similar to your field.
 
I live in them during the spring/summer time however I do make sure they are not ultra form fitting and I keep a cardi over the top to down it down slightly. I'd go for it!
 
Yes, absolutely! You can dress up the 'formality' side of things with careful consideration of accessories - I wear suiting-style dresses to work with closed-toe pumps and structured neat handbags. I will sometimes wear a jacket or trench over them to the office.

I live in dresses in summer, I loved watching Anna Wintour in The September Issue in all her dresses and neat skirts - obviously most of us don't work at Vogue, or even in fashion, but it's still a great source of inspiration for those of us trying to combine femininity AND professionalism in the workplace IMO.
 
I think it depends on your body type. The same way the appropriateness of a neckline depends on your bustline, the appropriateness of a pencil silhouette depends on the size of your booty. I have a big ass and would not wear a fitted dress to work, but I think if you are narrower it's probably fine.