Hi Khalimaroth,
The new Score Editor currently only offers a single page template (in Dorico terms). We will consider how we can offer a bit more flexibility in future, but it’s likely that your needs are best met in Dorico, if you need precise control over the header and footer items.
Regarding changes of font size, we will provide some more control over font styles in a future update. It may not be quite as detailed as offered in Dorico, but should go in that direction.
I agree, we should also provide further note properties. Accidentals in brackets are not currently available in the Score Editor.
Other symbols are actually available already. Enter a new text or system text item, set the Character style (first dropdown on the left of the inline editor) to “Music Text”. You can paste any symbol from the smufl glyph table directly.