Andre, I’m not the most qualified guy on this but I will step up since nobody else has. Take the free advice for what it’s worth.
You can import your pre-recorded audio into the timeline of the Motion interface and listen along to set your keyframes and in/out points. The only sane way to build a project like this is to have audio pre-recorded as a guide track. So go import>file> get your audio. Then make that a group and put it into the timeline interface window.
Just below the main viewer of your interface is a thin, one-line timeline where a player marker and a blue bar there indicates whichever track you’ve selected. If you play the project and listen to the audio, stop where the sentence starts, highlight the track of graphics in question (or create a new text object at that point), hit the “i” key to create the in-point, play on to the end of the sentence, hit the “o” key to mark the out point, or you can grab the end of the blue bar with your mouse pointer and drag it out longer or shorter, to get to the place it needs to be. Grabbing the middle of the bar with your mouse pointer allows you to drag the entire track forwards and backwards in relation to the overall composition, without affecting anything else, only what is selected.
The I and O keys will cut away the non-needed ends of the section automatically.
Now on playback, the activity, whatever it is, that you highlighted, will only take place within that specific time section of the overall timeline. Now you can set keyframes manually, or automatically, using the record button int he user interface, to make your flying type go where it needs to go during each sentence.
This is probably not the most elegant way to work, but it works for me.