SHIKECloud-Cluster Multicolor Rainbow Yarn for Knitting&Crocheting.Soft Wool Acrylic Cotton Blended Yarn.Gradient Space-Dyed Air Yarn (YT12)

Q: How many balls of yarn are needed for a baby blanket?

About 5-8 balls, it will vary according to the size of the blanket.

Q: Why is it so difficult to determine the weight of the yarn? Is it sport or worsted? Fingering?

I had the same difficulty. I am making a shawl with this yarn and it is thicker than a fingering/DK weight but not quite a worsted weight. I am using size 7 knitting needles and my measured gauge is 20 stitches and 25 rows is 4 inches. I wanted a loose drape to the shawl so I am using the size 7 but I think a size 6 or even a size 5 would work and create tighter stitches. It is a SUPER soft yarn. The skeins are huge - 458 meters or 500 yards.