Making the Perfect "Healthy " Banana bread

Won't you help me

Here's the original recipe, below that is how I changed it the second time.

l/2 cup butter
l cup sugar
2 eggs
l cup mashed bananas
l cup flour
l/2 tsp salt
l tsp soda
l/4 c whole wheat flour
l/4 cup oatbran
l /4 cup wheat germ
l/4 cup wheat bran
l/3 cup hot water
l/2 cup chopped walnuts

Here's my remake tried and true, I want to do something with the butter and the rest of the sugar though

l/2 cup reduced fat marg
l/2 cup sugar
l/2 cup home made apple butter or apple sauce (I used apple butter)
2 large bananas mashed,
l cup self rising flour
l/4 cup whole wheat flour
l/4 cup ground flax seed
l/4 cup wheat germ
l/4 cup oat bran
l/2 cup chopped walnuts

I think I can reduce the regular flour and use more whole wheat but i'd probably have to add the soda, I didn't add any salt to the recepe this time either

Can I use yogurt instead of butter?

Is brown sugar better than white sugar?

Thanks for the tips in making the Perfect Healthy whole grain banana nut bread.