Some bits about what you have asked were touched on in some of the devlogs, though admittedly not in great detail.
Right now, the primary plan is branching narrative, with some things shifting based on choices and interactions with others, but likely not to the extent that there are 500 million different paths you can take.
As for your second question, it's important to remember that this is still the alpha 1.0 demo, that I made mostly by myself. I mainly did it with my storytelling and characterization feet forward, as I consider those my strongest skills, so I didn't quite cover all that Ren'Py can do with it, especially with a self-imposed due date.
However, it's definitely going to be kept in mind for the next update, which will start to bring more of that into light. Plans are being made for choices to have some effect, and attempt to make use of more of Ren'Py's tools to keep things from getting too stale.
I just didn't get much chance to showcase stuff like that because I was rushing a bit, and also there weren't any real places to put things like that where they'd be majorly significant/noticeable.
Some slip-ups like certain things being known before you speak to certain jesters will also probably be gone back over and fixed, that was more an error in writing on my part, since again, it was all mainly on one person at the time ^^;;