I'm feeding my shubunkins the 'TetraPond Spring & Fall Diet' (floating soft sticks) that I purchased at PetSmart. It has wheatgerm in it that helps with early spring digestibility, but I don't agree with the recomended feeding temps on the package. It says to use the 'Spring & Fall Diet' in temps from 39*F to 50*F, and then all other TetraPond products from 50*F and above. I don't even start feeding until the pond water temps are consistantly above 50*F. Many of the seasoned koi and gold fish pond people here will agree.
I have shubunkins simply because I don't have the room for koi and they are typically as colorfull as koi. I don't have all the answers to you questions, but you will get a lot of help at this forum.
Happy ponding,