Is this knit neck-down, or bottom-up? It sounds like you're knitting a tube, but then you take 30 stitches off your circ needle and put them on a holder- leaving you with only part of the tube on your circular needle. This is the part you then work back and forth. You don't need an extra needle, though, you just use the two ends of the circ as if they were two separate needles. Yes, you flip it over and purl the wrong side, just like regular two-needle knitting.
The increases happen at the beginning *and* end of each right side row, so you're increasing two stitches in each of 5 rows. Two of those would happen in the 3 rows of chart you have left, then the other three in the 5 rows you work in MC after you finish the chart.
Hope that makes sense! If not, feel free to ask more questions.