@ancientFlyboy I want to understand more about your issue.
The theme sets the usable area on the projection screen, how wide and how tall the screen is, what font and font size you want to use and it sets the alignment of the text. (it does a bit more, but for this issue the rest is not important)
The Song in the library tries to set what text will be displayed in what order. It can also override the color, size and alignment of the text using Formatting tags.
I generally set the Theme to display as much of the area as possible leaving a uniform boarder to keep from projecting on the edge....10 to 40 pixels is more than enough in most cases. I have a flag on the left side of the screen that just can't be moved so 40 pixels lets my text stay off the flag!
Next I edit the song to display the text as I want it to be displayed. Imported songs are not normally setup for projection. They appear to be setup for the musicians or the choir.
There is one thing that can make your day easier....When you edit the songs, do it on the projection computer with the projector on. This way you are changing the song on the screen you are displaying it on. Sounds crazy, but it makes a difference.
When you edit the songs, some verses can be broken into separate lines with the 'Enter' key like the following:
Part of a song as it was downloaded....>
A new commandment I give unto you,
That you love one another as I have loved you,
That you love one another as I have loved you.<....
To fit my screen without running over, I first took line 1 and made it into two lines by using the Enter key...
>A new commandment
>I give unto you,
Then I added a split so only the two lines show as a slide. Different versions of OpenLP may have different options for splitting the current slide. I prefer the Forced Split option ([--}{--]) if it is available. With the Forced Split it will split where you tell it even when you choose the wrong spot. The Optional Split option ([--}) only splits the slide if the system thinks it needs to split the slide.
I continue to edit each verse of the song watching the live display to see what slides I need to change and if my changes look presentable.
For my use the slide text would look like this.
A new commandment
I give unto you,
[--}{--]
That you love one another
As I have loved you,
[--}{--]
That you love one another
As I have loved you.
[--}{--]
I hope this helps. If you are still having issues, just let us know and we will try to help.