Sounds like you're finding your way into the customization that you need to do. The Synopsis tool operates from pre-defined .sdf files, and editing those files is the only way to make adjustments. But they are quite editable, esp. the opening parameters, as you've discovered. I've got one called aland-nrs_grk.sdf, and its opening lines are:
/Versions GNT GNT GNT GNT
/Display GNT NRS
This gives me the Greek and the English in each gospel column. Of course you can plug in ESV or any version you want for the display. (I also just edited the above to replace GNT with BNT.) When you make changes, choose File > Save, and if you want to you can save it under a new name. This way you can have quite a variety of display options in the Synopsis tool; but you do have to load a different one every time you want to see it.
If you want to change the sequence of Greek and English in the display, that (I discover) is controlled elsewhere. In the main BW window, do Tools > Options, then under Bible Versions select Version Order. Here you can gain complete control over the sequence of versions in any multi-version window/column. Just put your preferred Greek version at the top, and it will also display first in each of the gospel columns in the Synopsis tool.