Space in lyrics and other text issues

ad 1: Ctrl+Space adds a space to a lyrics syllable. It does in 2.0 and did in 1.x too.
ad 2: as mentioned in another thread, it is difficult to day witout seen the actual score, but maybe a vertical spacer up would help here, or changing some settings like music upper distance or frame lower distance
Edit: now there is an mscz file... and indeed frame lower distance does seem to work well.
ad 3: one option: append a vertical frame, add frame text to that.

1) Not sure what difference you are expecting to see betwene the | characters and the I character - it will depend on what font you use. In FreeSerif - the new default font - the letter "I" has, well, serifs, which | does not. So to me it is obvious enough that isn't a letter I. But you are welcome to use a different font you prefer. MuseScore formerly used whatever happened to be on your system, meaning your score looked different on every system because every system has different fonts. That is why we decided to provide a font that would be used by default, so people could be assured their scores would look the same on all systems (at least to the extent possible).

2) It looks like the text is larger than frame. Not sure if this was the case in 1.3 as well, but in general, you should not have text extening below the frame. If you want the text lower, resize the frame, don't move the text down. So select both the composer and lyricist text, press Ctrl+R to reset to default position, then resize the frame as necessary. This will create the correct amount of space.

That might be all the space you need. Since you've already saved this in 2.0 I can't load it in 1.3 any more to compare, but if you were expecting *more* space than fixing the proboem with the composer & lyricist text provides, then my guess is, you were relying on a bug in 1.3 that has been fixed, where 1.3 would include *both* the "Music upper margin" and "Vertical frame lower margin" settings from Style / General between the title frame and the first line of music, when really, "Music upper margin" should only have applied to space between the music and the page margin. It was thus impossible to get independent control of these parameters. This is improved in 2.0, but it means that scores that formerly relied on "Music upper margin" to control the distance between the title frame and first line of music need to be adjusted. This is just as I guessed in my first response to your other thread :-)

3) Depends on how exactly where you want it to appear and how you want it handled should the formatting of the page change. If it's literally a page footer - supposed to be on the bottom of the page no matter how full or empty the page is, then Style / General / Header, Footer, Numbers. If it's just text that should appear immediately after the music, then appending a text or vertical frame would be the way to go.