what (not) to wear in Dakar

I'm packing.  Here's a picture:

This is a difficult process.  Trips to the pharmacy aside--to pick up obscene amounts of pads, tampons, and malaria medication--I still have to journey back and forth to my closet, trying to guess what is acceptable dress in Dakar.  Here's what I know so far:

1. Low neck-lines are inappropriate; same for short skirts.  All dresses/skirts should go below the knee.  This is tricky, because it gets hot in Dakar.  It's supposed to be 60 - 80 degrees F while I'm there, and I can't wear shorts or tank-tops.
   
2. Men and women care a great deal about their appearance, especially in public.  All the casual American styles I own--plain t-shirts, slightly frayed jeans, cracking sneakers--are really not up to snuff. 
   
3. Students at the university dress up for class.  What "dress up" means, I'm not sure, so I'm taking a few collared shirts that I haven't worn since high school.
   
4. Young people wear western clothes.  Young, urban women wear pants.  This is good news, though I still intend to take advantage of cheap cloth and clothing prices to get some traditional outfits tailored to me.
   
5. When exercising, shorts are fine.  This I learned from writing to another young woman--a runner--who's currently studying abroad in Dakar.  I had nightmares of heatstroke while running in pants.
6. When clubbing, anything goes.  Outfits get much more daring at night.  I don't feel very daring, though, and so I'm not taking anything that would be too revealing.  (What, I wonder, would they think of the clothes Yalies wear to the Screw?  On Halloween?  To Toad's?)
   

As a toubab (a white person), I'm going to stand out no matter what, so I've got to find a balance between comfortable and conforming.  In short, I have no idea what to bring.