Regarding your first request - Press Command+Shift and click on a tool to drag it to a new position in your palette. It will swap positions with the tool icon you land on. Put your offending tool icons at the bottom - then resize the palette by clicking/holding on the lower right corner and resizing the palette so the tools you want hidden are no longer visible. It's not perfect but will remove your unwanted tools from view.

In the image below - I rearranged the simple note entry tool and the midi tools to the bottom of the palette and resized the palette to "hide" these tools. I also rearranged a couple of other rarely used tools. I'm using Finale 26 - Mac OS.  Also - the help page that could indicate this "feature" has an error at the bottom - the complete help description doesn't appear... it ends with the word "view" followed by a comma.  (some might say this error is "typical MM attention to detail"...)

Thanks. Yeah I’ve done that too but it doesn’t always stick. It is certainly a workaround with which I’ve made do, but why can’t it just work the way most Mac apps would? Even Microsoft apps give some ability to hide specific toolbar elements. 

I agree... could be a nice option... that said...

My most frustrating manual adjustment peeve: I would rather they fix rehearsal mark and measure number positioning when they appear at the start of a system so we don't have to reposition every one manually in all score pages and parts. Both Sibelius and Dorico have multiple settings for how to position a rehearsal mark or measure number at the start of a staff/system... Finale? (crickets...)

Centered above/below clef or time signature? Or maybe a user-defined positioning option similar to the existing positioning dialog boxes for mid-staff positioning? Anything would be better than manually positioning start-of-staff/system rehearsal marks/measure numbers on EVERY start-of-staff/system occurrence. It gets very time consuming on a score with 300+ measures and 30+ parts...

2. The ability for Finale to behave like any standard Mac app and remember where I left the Tool Bar and Playback Controls. Both always seem to end up on my other screen when I start Finale, even when I've dragged them where I want them on my other monitor. 

There seems to be a problem when 2 monitors are used (all versions, Mac). Finale doesn't memorize the position of the palettes and Playback Controls. I have reported it to MakeMusic, but nothing solved the problem.

Each time the Mac or the monitors go to sleep, the problem occurs, too, and even the size of the main window gets modified. The time lost (several times a day) to rearrange things is substantial.