Formatting

Style> Edit General Style> Page
Put a check mark on the Create key signature for all system
(and uncheck the Create courtesy key signature instead of hiding them)
It may be fine to start with?

---------------
it is easier (for me) to attach an example:
Staves third intervals, right-click / Measure properties = 7/1 (it seems more balanced);
Analyze settings of> Style / Edit General Style:
Page;
System (fix number of measure).

Can it go?

1. I don't understand what you are saying about key signatures. I can put key signatures in anywhere I like in your score, either staff, any key signature. But because it appears you have turned off the option to *display* the key signatures at the start of systems (Style / Edit General Style / Page / Create key sig. for all systems), the key signature doens't *display* at the start of a system - only if you change keys mid-system. I assume you you must have previously disabled this option yourself, because it defaults to being on. Maybe you turned it off because on some staves you *don't* want to see the key signature? If so, then better to just hide it on the staves where you don't want it.

2. As for staff distance, the short answer is, you cannot *decrease* distance for two one system only - you can only *increase* it. So if you must have one system tighter than the others, set that to be the default, and use a spacer (see Breaks & Spacer palette) to increase it elsewhere. Generally, though, this is *not* how one would normally go about fitting more music on a page. Much better to reduce the staff or system space by a small amount globally, and/or reduce the overall size of the notation via layout / page settings / space. But what you want is actually different - you want *less* music on page 1, right? That's easy - just add a page break from that same Break & Spacer palette.

3. See my comment in #1. You *did* disable key signatures at the start of each system; that's why they don't seem to appear when you add them. But that option should is only for use when you truly don't ever want any key signatures to appear at the start of a system. If you want key signatures sometimes but not other times, then you should just hide the ones you don't want. In your case, though, I don't understand what you are doing at all here. You have a key signature of G major (one sharp, F) on many parts of the first page, but you aren't showing that key signature. Why bother having it? The whole first page should be the key of C, should it not? Then you wouldn't have needed to hide anything. It sounds like maybe you want the whole first page to be key of C, the whole second page key of G (one sharp - F#). In which case, you should turn key signatures back on, delete the numerous key signature changes you seem to have added, and just add the one going in to the second page. Unfortunately, I can't seem to delete all the spurious key changes - I suspect all the mucking about that has happened so far has corrupted your score. I could be wrong, but if I were you, I'd start over with a fresh empty score, and this timer only add key signatures on the page changes, and don't turn key signatures off - just hide the ones you don't want. I would also question why you are hiding anything - why not show the key signatures on every system like regular music does?

In the future, it's better to start separate threads for separate questions - it can get kind of convoluted following discussion of so many unrelated issues in one thread.