Some B6 is stored in muscles for short periods of time to aid in metabolizing glycogen. It is stored as pyridoxal --the active form and not pyridoxine as is found in most vitamins.

The enzyme in the liver that converts pyridoxine to pyridoxal phosphate, is called pyridoxal kinase. It has been found to be blocked by some drugs. But not all drugs have been studied in this regard. Pyridoxal kinase uses as a cofactor the Vitamin B2 which is riboflavin. If this is low, then B6 cannot be activated properly.

And yes, typically the high dose B complexes are excreted quickly in the urine. The bright yellow is usually the B2 riboflavin showing up. If you take B6 alone, the urine would be lighter with a greenish tint. Excess B1 can give a yeasty odor to the urine or sweat.

I think taking the others you list would be ok, unless those are being tested also.