I think in USA, much of it any way, He sees her. Would be how many pronounces it. With the h being silent. Similar to #2 in your list.
Oddly when talking about the person I pronounce it See-Ser but when talking the salad I pronounce it like See-Zar. Not sure why the difference.
see-zer except the z is somewhere between an s and z sound, and proceeding e is somewhere between a and e. also the s is a little bit more of a short c sound, such as the pronunciation of cereal. (the tongue comes out a little bit further when making an s sound compared to a soft c sound) So maybe I could write csee-szaer but the ae would be a shorter pronunciation
The German way might be actually quite near the real Latin. I once learned that the italian way "tchésàr" should be quite correct.