I have this cup; I bought it in-store.
There is a space where you could use a straw, but the opening is clearly designed for sipping thick drinks, so, if your cup fell over with a straw inserted, it would leak. I find the sipper/opening to be perfect for my thick smoothies.
No, it isn't insulated.
If the item listing says, "assorted" your color will be random; the only way to get the color you want is to go to a brick and mortar location and pick one out.