CrocsIsabella Jelly Flat W, Womens

I want size 8 but only size is 4? I am unable to select size on site

I'm a size 6.5. should i get size 6 ot 7 since they don't have half sizes? (my feet are not wide)

Would these be good for day-long walking in europe? i read a review on a different site recommending them, “worn 6 wks in eu walking 10 mi. daily”

Will these stretch out over time? I am normally a size 6.5 and tried these on in both a 6 and 7, the 6 fit very snug, and the 7 fit a little loose.