Adding fresh fruit to a non fruited banana bread
If you add chocolate and nuts, no. They can be added without any adjustments, as they don't tend to affect the rest of the cake at all. Fresh fruit is a bit trickier, since it tends to release a great deal of liquid when cooked which can make the result soggy. In general, if you add fresh fruit to a cake you want to toss it in some starch (eg corn starch or potato starch) to absorb the liquid it will release. Each piece of fruit should be completely coated and then just folded into the batter.