I think in this pattern the yarn forward twice instruction is meant to be the same as a double yarn over. I think this is the case because they refer to it in the next row as a double yarn forward. You need to end up with two yo stitches in order to do the next row. You knit into the front and back loops of each of these stitches. This is probably why you have too few stitches.
As for the 'knit this stitch again,' it's probably to avoid someone asking, Should I knit that stitch I already knit or what?" It's just a way to make it a bit clearer which stitches you should be knitting.
"Trust the pattern!"
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IngridKH on Ravelry