Vibram FiveFingersWomen's Spyridon MR Elite Running Shoe

I wear a size 10 in women's. Would you recommend a size 41 or 42?

i were a size 8 1/2 what shoud i get?

Well im a 6.5 US... should i get the 36 or 37???

If I accidentally stepped on cacti, would the sole be thick enough to prevent the punctures?