.Looks like the second study is actually easier than the first study
Sort of. If you are in the process of learning scales, then #1 would actually be easier since you only need to know 1 scale, the chromatic scale.
.the Arban's book looked even more intimidating or at least from a where do you begin
Again, get some input from your instructor. There are easy and hard parts of this book. Depends where you are in your progress and what you need to work on.
There are no shortcuts. You should learn them all. Spend the most time on what is diffucult until they are all played equally well.So far as scales do you recommend learning and practicing all major/minor/chormatic scales, etc. or are just certain ones primarily beneficial?