so you are knitting in the round, that's what your plan is? (On circular needles you can knit back and forth or in the round, both works).
pretty much what you want to remember is: a knit is a purl and a purl is a knit - just seen from the other side.
So when knitting in the round, you work on the Right Side of the fabric only and therefore all instructions for the wrong side will need to be reversed from knit to purl and vice versa.
For example: if you do your few rounds in just knit stitches, you produce stochinette stitch, because the fabric forms like one that is one row knit and one row purl in working back and forth. In the round: all knits.
So those top and bottom ends will curl, that much is for sure.
Would you want garter stitch (which would be all knits in working back and forth), you will have to knit one round, purl the next and so on.
Raspberry stitch will be nice looking and feel thick because of the bobbles, but there will be holes inbetween the bobbles, so this will not be the most wind tight cowl. Just for you to know.