As for the default font, that is not a bad idea but need to figure out where to put it since we do not have control over the font dialog itself. For now, when using Text: Simple, you can create your own Preset that sets this and then choose it.
You are supposed to add these effects yourself using other filters with keyframes. We are not going to add existing effects into other existing effects. For example, you can add Glitch or Nervous to a text clip. With that said, we do hope to add some text-specific effects such as typewriter or changing the letter spacing.
The next version lets you drag the rectangle from anywhere inside of it when you are holding Shift (and there is a message that appears to provide that hint). If the rectangle is all of the way off screen, you still must zoom out the player or change the numeric values.
You need to report a bug in order for it to be fixed. If you find a bug start a separate thread, put it in the bug category and answer the questions that are asked to you in that bug form.