Am I feeding a good diet? Advice on balanced diet

I'm fairly new to owning mice and I have done plenty of research about nutrition for mice, but still unsure if I'm feeding a correct balanced diet.
My base block food is Burgess Supa Rat Royale as I have heard it meets all the nutritional needs of mice. I supplement there diet every second day with oats, dried brown bread, brown rice, leafy greens, carrot, red grapes, blueberries and for treats pumpkin seeds, sunflower seeds and pine nuts. Am I feeding them too much supplements?

Opinions appreciated