All in all I found your guide pretty straightforward and agreeable. I think that you overstate its applicability, since it's tailored for very thin people like yourself rather than for overweight people (the majority of people that start training). I do think it's good that you focus on motivational factors, as that is ultimately by far the most important thing to success in fitness.

One point is that muscle memory is probably a real effect. There is a very approachable article on it on Strengtheory although the site is currently down. There is a cached version at [0]. Basically, as your muscle grows it creates new myonuclei, which is energetically expensive, but those myonuclei are not lost when you detrain. You need a certain density of mynuclei to support a given volume of muscular tissue. There is also a brief description on Wikipedia with references [1].

Another thing to note is that the main benefit of compound exercises for bodybuilders is that compound exercises are much more time efficient than isolation exercises. With regard to the specific exercises you've selected, a few criticisms come to mind. 1. I don't think oblique work is necessary in a minimal program focused on aesthetics. Most people do not need a specific focus on larger obliques. 2. On your leg day you are progamming 4 sets of squats, 3 sets of hamstring curls, and 4 sets of deadlifts. The hamstring curls are at best unnecessary. The hamstring is the primary mover of the deadlift, and squats also work the hamstrings. It would be better to program barbell hip thrusts to develop the glutes. In general you should add specific glute exercises for an aesthetic-focused routine targeted at both men and women. 3. The seated pulley row and lat pulldown work substantially the same muscles.[2] They should be separated in the workout at least. In general I'm pretty skeptical of bodybuilding split type workouts for beginners. I think it makes more sense for beginners to do full-body workouts, as the hallmark of being a novice is that you can make strength gains every workout. Body part split routines are necessary in part because intermediate lifters require more time for their body parts to recover from a given exercise, so working a body part once a week makes more sense.[5]

It is probably not the case that 4 sets is "ideal" for hypertrophy. There are diminishing returns, but not negative returns, and 4 sets is certainly not enough to get "maximum hypertrophy" as you claim in your addendum.[3] Part of the reasoning failure here is that you claim that it's impossible to lift with middle amounts of reps for more than 4 sets, but that is probably not relevant, because what matters for hypertrophy is the number of sets you do to near failure. Being within the magic rep range is not very important.[4]

I think that's all the criticism I have time for now. Seems like a good start, and hopefully you can use some of this information to improve the guide.

0: http://webcache.googleusercontent.com/search?q=cache:pl8tNHF...

1: https://en.wikipedia.org/wiki/Muscle_memory_(strength_traini...

2: https://www.t-nation.com/training/inside-the-muscles-best-ba...

3: http://webcache.googleusercontent.com/search?q=cache:X6nFkck...

4: http://webcache.googleusercontent.com/search?q=cache:L6EENZs...

5: I believe this is discussed in detail in Practical Programming for Strength Training by Rippetoe.