Although the ratio of oil to acid is a matter of taste, most basic recipes begin at 3 parts oil to 1 part acid. You might consider reducing the amount of vinegar you use.
A very basic vinaigrette will use oil and vinegar, a bit of dijon, salt and pepper and maybe a garlic and a pinch of sugar. A t of chicken stock or soy sauce are "restaurant secrets" to make it more savory.
Personally, adding 1/4 cup of honey or syrup would be WAY to sweet for my taste, especially with the balsamic vineagar. But that's also a matter of taste.
Also, 2 tablespoons of rosemary seems overpowering to me.
Anyway, for the "missing something" component, try adding, soy sauce, anchovy paste, chicken stock, a bit of white miso, or worcestershire sauce. They will all add savoryness (umami) to your dressing
Less is not more. More is more and more is fabulous.