No problem at all with using p90X... P90X is tough stuff.
For white flood, no cycling is required... totally optional. Though some people like to cycle it because of the stims. But it's up to you and how your body handles stims.
As far as the Purple Wraath vs. Green Mag, they are two different products with different functions. Personally, i take both. Along with the Aminos, Purple Wraath has a nice endurance complex which is excellent for cardio.
For Green Mag, not only is it an excellent creatine product, but it's more than that. Among the many benefits, Betaine Anhydrous aids in the oxidation of lipids (fat) which is exactly what you want during your cardio sessions.
The sup schedule you have planned out looks awesome to me.