It's a fun as well as a challenging book, you did well!
On baroque guitars, they were usually tuned reentrant. Lots of different tunings exist, most in five double courses, but all of them with at least one, sometimes even four of the 'closest to the nose' strings tuned an octave higher than expected. They were crucial to the campanella effect: mixing as many strings as possible into a single melody line, so that notes ring out. Tablature predates baroque guitars, but the instrument was instrumental in the development of the 'letters for chords' system.
That evolution towards chord progressions is typical for baroque music: as a musician you are supposed to ornament and improvise yourself, the sheet music is only the basics. It was the jazz of its time; even the name 'baroque' means 'misshapen pearl'. It also introduced a stronger emphasis on tonality, being the particular key the piece is written in, with your circle of fifths giving tension and release; unlike the earlier 'floating' modal music which didn't emphasise the key with its first and last chord.
In addition to the players mentioned above, check out Samantha Muir and Valéry 'Ukeval' Sauvage. You're in for a treat!