And was any of its messages (such as, SOS) vocal? Or was it just written?
Tempting Apple: No, that was what they were using on the Titanic to send passenger's messages with a spark gap transmitter. Not sure what you mean by vocal. Not human voice, for sure. It was sent with a manual key (a switch, basically). The operator might receive it as clicks in a headphone and then write it down as letters, though wired telegraphy commonly used ticker-tape where there was a paper record of the actual morse message (hence ticker-tape parade in wall street, where they tossed the used tape out the windows) .
Morse was also used in Aldis lamps for optical signalling, right through the second world war. The navy has only recently given up morse completely.
(as a recreational boater with no friends on the water, my VHF transmitter was pretty much reserved for distress calls until I started using a swing bridge I have to call to open. But most operators then as now would use radio – and morse – for operational traffic)
No. Morse code is used in telegraph and ship to ship light signals. The telegraphs of the old west used Morse code. Later, radios (wireless telegraphs) used Morse, too. This was before voice transmission was common.
No, morse code was used for decades to send telegraphic messages (telegrams). Each letter is made up of dots or dashes or a combination of both. It's just that SOS is the most famous one (dot dot dot dash dash dash dot dot dot).
Mostly. But also used anytime the only way to comminicate is by 'tapping' or pulsing a signal.
No. Was (and is) used from telegraph communications and some transmissions at sea (distress and general exchange of information). Think of it of texting before we had all these "wonderful" devices of today…
No. Not at all. It was used for all sorts of communications.