Hello @Tonemdra,
I just started this course, and am assuming that the hyphenated forms of the words are the plurals, with a quotation mark for an umlaut applied in that form.
Correct.
Also, in level 3 ‘der Gott, "er’ has no hyphen - is this significant in some way, or was it just missed?
Thanks for pointing this out. It was indeed an error. It is fixed now.
Although I doubt anyone just starting out in German would begin with this course alone, is there any kind of introduction I need to read/are there any other rules unique to typing for this course I need to look out for? I’m going off my own assumptions here, but it might not be obvious to people just starting, who are less familiar with plural forms.
Besides the plural, there is no other rule. This is not a grammar course. For instance, the inflected forms are not included (e.g. wem and wen are the dative and accusative forms of wer, and do not appear).