Need help with sleeve

I have knit the cuff on a sweater and then worked 2 rows of stockinette (per the pattern). To start the increases, the instructions then say:
(On Right side) K2, M1R, knit to 2 stitches from end, M1L, k2. Work 21 rows in stockinette as established. Work the 22 rows above 2 more times, for a total of 3 times–44 stitches. Work in stockinette stitch until sleeve measures 16 1/2" from cast-on edge. End with a wrong side row.
After this, I start the sleeve cap.
I have 2 questions: (1) After the first row, which is an increase row, the second row is a purl row?
and (2) I’d like to add about 6 rows to lengthen the sleeve. Where is the best place to do this?
Thanks for listening.

Yes, the second row is a purl row.
You could add the extra rows after the shaping is finished or you could increase the distance between increase rows by 2 rows in each set of 22.

I get it. Thanks so much for answering!