From the original post:
In fact, you can: in the Preferences dialog you can choose the default text font for new projects, so if you change that before you start a new project, all of the text both in frames and more generally around the score will use the text font family you choose there.
To the extent that these things would require the addition of Engrave mode to Dorico Elements, the answer is no: but it may become possible to do some of the other things that you mention (e.g. adding carriage returns in the various fields in Project Info) in the future.