Well, to bind off, you slip a stitch over a stitch, so you may end up using one stitch more but that stitch stays on the needles. As for the counting, do what works for you. Write tally marks on paper, use a counter, etc. I personally just go and if I lose count (on purpose or accident- I know, sometimes I'm kind of lazy at counting lol) I count the bound off stitches I have already done. You can see them pretty clearly when looking at the exact top of the stitches... they're a sideways u shape that's pinched on the open end. This pattern looks like it has you bind off at both sides and is worked flat.