Hi. when you say splitter you mean you have one output and that output is split between a monitor and a projector? If so, you need to make sure both the monitor and the projector have the same settings, eg 16:9, 1920×1080. The projector and/or the monitor may also have modes to zoom/fill/fit/narrow/etc – you need to try all those settings as well.
To set margins for database items, you can do so via Manage -> Databases. Then change the left and right margins.
To set margins for Bible passages, you can do so via Manage -> Holy Bibles. Then change the left and right margins.
One other method is to change your Live Screen to custom:-
1. Settings->LiveScreen
2. Click the screen info icon beside your Live Screen location and note the Left, top, width and height values.
3. Change the monitor to Custom and copy the Left, top, width and height values you had noted in step 2 above, then change them slightly to fine tune your position. Click apply. Go Live. This will help you to slightly re-position and/or re-size your live output.