To animate text in VEGAS Pro without having to use multiple text presets, follow these steps:

1. Add your text to the timeline and drag the edge of the text event to resize it to the length you want. 
2. In the text event, click the "Generated Media" button to open the Generated Media Properties.
3. Type in the first word in your text string. For example, if you want to animate the phrase "sample text", type in the word "sample".
4. There is a timeline at the bottom of the window with multiple keyframe buttons. Let's say you want the word "sample" to appear immediately in your video, and you want the word "text" to appear at the 1-minute mark. To do this, click the 1-minute mark in the keyframe timeline and enter "text" below "sample" in the text field.

It's important to make sure the play cursor is set at the beginning of the clip when you do this. If the play cursor is set somewhere in the middle of the clip when you add the keyframe, the word "text" will be added after the 1-minute mark.

You can also use the technique described here to animate the position and color of text.