I can not difinitively answer all your questions, but I will do the best I can. To read/knit a chart you start on the right and knit across to the left. (So that the stitches go onto your right needle as you read them off of the chart.) It makes much more sense as you do it. As to adding the chart, I can make a guess as to what I would do. Knit up however far you want the bottom of your chart to start. Then add a stitch marker (I’m thinking you could just use the one marking the beginning of your row.) and begin the chart. When you finish the first row of the chart, just go back to the regular pattern, until you get to the marker again, then do the next row, and so on. (And because I am just that way, I would add a marker to make sure I finished the chart in the same place each time, especially if you are switching colors in there.)
Hope that helps some. I am sure someone with more expertise and a better way of explaining will come along a give you a better answer!