As Far As I Can Tell, those features are already in Finale.

If I misunderstand you, then I apologize.

What is the problem you are trying to solve?

Ruler view that shows tenths of inches rather than standard sixteenths

You can already choose Inches as Measurement Units, and the measurements will display decimals in Finale’s dialog boxes.

Indeed the Ruler displays sixteenths of Inches rather than tenths of Inches.

If I understand you correctly, your request is an option to display tenths of Inches in the Ruler, right?

Correct.  I understand that Finale is not a desktop publishing program, but for example in InDesign, working in an "inches decimal" environment is a lot friendlier when you are trying to work with design and layout staff who are providing inch/decimal measurements for many different aspects of laying things out on the page.

Not sure how useful this would be for everyone, but for me it would be helpful if there were an option to snap guides to increments on the ruler. For example, snap guides at every [user defined increment], 1/8 of an inch for example. I realize you can edit precisely where you want the guide to be, but this would speed things up.

Also, the increments on the ruler disappear after passing over it with the guide so it's hard to at what point the guide is on the ruler. Not sure if this is a Windows only thing.