For post 2 regarding Vit B6 intakes over 100mg being bad for you, you might be thinking of studies that used IV injections and not oral dosing. Oral toxicity for Pyridoxine HCl as used in Poseidon has not been shown to occur at the low doses we're talking; perhaps if you're taking 1g/day.
I have been adjusting by Poseidon intake to my exercise/sweat production; if I do a 50 min. fasted cardio session & lift, I'll probably take 3-4 scoops during those workouts. On an off day, I might just take 1-2. As for the multi-vitamin, it might not be necessary with a proper diet; it's all individual. If you're cutting and not getting as much nutrients as normal, it might not hurt to take an iron-free multi at even just half the daily dose to help ensure you've got the basic nutrients. A nutrient deficiency will be harmful to your progress, whereas vitamin/mineral toxicities are generally hard to come by.