Hi Don,
After turning on Genos, look at the small screen currently labelled B above the sliders. You'll see a row of titles: style, m. Pad, Left, Right1, Right2, Right3 and so on. So Genos has already set up the sliders to enable you to change those volumes you mentioned. If B is not highlighted anytime, push the Slider Assign panel button until it is.
If the style volume then changes at some point it must be because you have activated a registration which was saved to a different style volume. So to counter that you need to use the slider again after using a registration to reset style volume. Once reset you can continue playing, or better, decide to rememorise the registration there and then so next time it comes up with the right value. After pushing memorise make sure you have at least style and voice checked, (and probably others such as tempo, harmony, transpose? It depends on what you need).
Once you have saved to all the buttons in the bank for that session make sure you then save the bank to make the changes permanent. If you are concerned about making mistakes, save the bank at first to a slightly different name, so you still have the original.
If you want to save different voice balances at the same time you can adjust them first using their sliders before memorising as above.
John