So...after much self-shaming and coming to terms with the fact that I've derped up by not grabbing Blood for Blood earlier in my NIN career; am I ok to finish out the MSQs, hit 60, and then go back and level Lancer to grab the skill? Or am I not going to be able to finish the content without out for some reason? At the time of this question I've just finished clearing Bismark (story).