Hello, I'll try to answer your questions as best I can.
First, there are 2 kinds of sunflower oil: Regular and High Oleic.
Regular is high in linoleic and linolenic acids (poly unsaturated fatty acids) which make soaps more likely to go rancid. If you put your recipe in the calculator, be sure the amount of linoleic+linolenic stays below 15%. This will also depend on the other oils in your recipe, so it's difficult to give a strict maximum for sunflower oil (I've mainly used around 15% myself)
High oleic sunflower oil contains mostly oleic acid (mono unsaturated), and you can use it as much as you want. Be aware, a lot of oleic acid in soap (>50%) means a longer cure and some people feel like the soap is slimy.
I use citric acid at 2% of oil weight. Make sure you adjust the amount of lye (more info on
this wonderful website)
I've never used anise water in soap and never heard of anyone using it, but I think it should work fine in soap. (If you want the scent an EO/FO is more likely to stick around though.)
Hope this helps.. happy soaping!