for the shoulder:
do some rotator cuff exercises, concentrate on external rotation mostly
as this is much weaker than the internal rotators, generally speaking.
but i cant really give specific suggestions without knowing specifics about your shoulder.
you may also be over working the shoulder, bc it gets worked in back, chest, shoulder workouts, as well as bicep tendon may also play a part in the shoulder.
I am not a firm believer in doing abs every day.
I dont really have a six pack either. LOL.
but I would say, nothing is written in stone.
if your abs are still sore or aching from the previous session, its ok to skip a day or 2 on abs.
I personally only do abs once a week, like any other body part.
but again, my abs are nothing to write home about.
isometrics, waste of time.
if you can do isotonic exersice, do it that way.
there are certain techniques of using isometrics, like on the power rack, and isometric contraction is stronger than isotonic,
eccentric, or negative training may be beneficial, but use sparingly.
but as a whole, training is very individual.
what works for me, may not work for you.
a lot is trial and error, particular to the individual.
but sounds like your training is coming along great.
you have goals and measurements to track progress.
you'll make your goals, I'm sure!
