I'd definitely recommend posting a suggestion on the Microsoft Feedback re a toggle for "Spread view". However, the ability to have an object spanning the spread view would be more of a stretch I expect!
If I had that as a requirement, I'd probably "fake" the spread in a separate section set up to print the 2 pages as a single tabloid-sized page (or a suitable landscape dimension). The challenge would be to know how to deal with the gutter though: maybe not a big problem in a thin booklet, but certainly a factor in a larger book.
As for managing bad page breaks with footnotes...
- If it is caused by a footnote that occurs in the last few lines of a page such that Word will not be able to fit the note on the same page as the reference number, it will have to break the page short. In that situation, tightening up content on the page may make up a line or two to make it fit; if not, you may need to tighten things up for one or more pages prior to the bad break.
- If there appears to be sufficient room to fit the full footnote at the bottom of the page, check for "space after" in the footnote style & remove it. Otherwise, as above, tighten up content on the page (and page(s) prior to it if necessary).
If this is something you do frequently, consider customizing your Word ribbon to give you access to tools you need to use. I've been preparing fairly specialized multilingual books for print and PDF publication for many years, and the final pagination has always been the "last minute" task. The screenshot below shows my custom "Pagination Tools" ribbon set up with commands and buttons to assist with doing the otherwise tedious layout tweaks for paginating documents.

Some items are commands available in other ribbons: for example, my "Page & table layout" group includes Page Setup, Table Properties, Split Table, Borders and Shading, and Text Direction buttons.
Other groups provide access to built-in commands that are unavailable in any ribbons (such as the very useful but-hidden Frames feature), or run custom macro code. Buttons in my "Squeeze & expand" group will run custom macros to increment or decrement Leading (line spacing) in 5% steps (+ a "Leading Reset" button to reset back to the style's default setting), and similar macros to alter the font spacing. These are very useful for tightening up content: I just select a suitable chunk of content above an awkward break and click the buttons.
Affected paragraphs will show the tightening strategy as "Direct formatting" in the Reveal Formatting pane when "Distinguish style source" is turned on, but I have other custom macros to remove any such tightening if the document needs to be repaginated for a later edition after editing.