Yes, HSC can be considered circuit training. I certainly include it in this category.
It's hard to answer the question of "is this enough weights" because that depends on what your goals are.
Are you saying that you do Circuit Max, High Step Challenge, S&H legs and PH every week? With just cardio routines in between? That's a lot of endurance work for the upper body. Have you ever considered doing split routines for increased strength work? Endurance and circuit training can only build strength to a certain degree, then you need to change up your program and use the GS series, or PS series or S&H series to go beyond that plateau and build greater strength and therefore definition.
Clare