this is an easy question to answer: Birds all of them should eat everything that is healthy for us, no junk food, zero avacado's, you feed avacodo you will be digging a grave: there are many sites that give you lists of what you should feed and what you should not: there is also a sticky post somewhere on this feeding frenzy that will tell you what you should feed and what you should not: One source of learning what to feed and not to feed is
http://www.birdscomefirst.org
aS PER THe sun flowers sun flowers are candy and they can cause fatty livers: salt? Absolutely no seasonings at all: none!!!
As per favorite and can't and won't eat fruit, its a trick you mix proportion to proportion, first a little heavy on the sun flowers but not nearly as much as youve been feeding, then mix a little of the fruit or feggies with it be sure you place the seed where they must also take a sample of the fruit, and then gradually change the diet over. It takes time but it will work: get your bird off of the sun flowers as quickly as you can.
This hopefully will help you out