Everything is working within the current parameters, for what it’s worth.
Dorico only changes the text font when you switch to either Bravura (in which case it changes to Academico) or to Petaluma (in which case it changes to Petaluma Script). So if you change to Petaluma and then to another non-Bravura font, text will remain in Petaluma Script.
In the recently released SMuFL 1.4 standard, it is now possible to specify a preferred text font family in the font-specific metadata file. Dorico 3.5 does not currently support this new addition to the font-specific metadata file, but it will be supported in the next major version of the software. You may wish to include this in the meantime: Bravura’s latest version does, for example.
As for the clef changes, at the present time there is insufficient information in the font-specific metadata files to make it possible for Dorico to automatically switch to optional glyphs (i.e. those in the U+F400+ range in SMuFL) when switching font. When I’m ready to start work on SMuFL 1.5 (which won’t be in the immediate future as we’ve only just finished SMuFL 1.4 and there are several ongoing Steinberg projects to which my time is devoted at present), this will be one of the main things I will aim to sort out.