That’s the spawn shield countdown. However, you are right that it does appear briefly while outside the screen, so I’ll fix this for completeness sake. Fixed in v.116 
Bug
Isn’t the scoreboard still visible while the game is paused?
indeed!
This was done to preserve network bandwidth. Granted, it only saves 2-4 bytes, but it’s 2-4 bytes that I have to pay for, so… acknowledged; won’t fix 
The problem is that the tutorial appears on two different screens with different layouts. Fixed in v.117 Bug
It’s not “bugged” as such. It’s just how the filter works.
It’s too translucent, so the filtering has made it transparent. I’m ambivalent about this, but I’ll exclude it from the filtering. Changed in v.117 Idea
Funnily enough, yes; that’s how I fixed it.
CI2 doesn’t have menu music (at least not the original 2002 version). Anyway, it’s only a test for now. I’ll see what other changes need to be done when the 20th anniversary approaches.
It does have music assigned – it just happens to be the same as the Retro wave music.
Meh. If I start explaining everything on that screen, the tutorial will become unwieldy.
Will add.
Changed in v.117 Idea
Fixed in v.117
I’d say leave them in English.