vincent13 A short review based on a quick playthrough:
Write dialog like dialog. Don't include non-verbal cues in the character's speech. For example:
This is an action description:
Nods, still taking in the beauty of the mansion
This is dialog: "Great, thank you. I guess I'm still getting used to the idea of owning all this."
They should not be mashed together. It makes things incoherent. Especially when certain assumptions by your audience are made. Those assumptions being that if you see a character's name on the dialog box, they are speaking.
In general a lot of renpy games will use the narrator voice/dialog box for things like action descriptions, etc.
*Edit: It seems later on you do in fact separate actions from dialog. Then after you do so, you revert to mashing them together, but delineating actions in parentheses.
I guess whatever you ultimately decide to do, make sure you do it consistently. Good luck on your game.