Thank you for your comments @Henry Ng Tsz Kiu @Omicronrg9
I understand what Daniel means with the lack of expresivity but my intention was more like what Henry said. For me, in this style, is more up to the interpretative process than the arranging, so I wrote only a very few expression indications stated by Stanley.
About the harpsichord... Actually, my intention was to leave a basso/continuo line and indicate when to play only cello solo and tutti, and not to introduce the harpsichord. I like the sonority it adds but, as Daniel said, now I also think that indicating it but for only doubling bassi is a waste (but now I'm not really interested in writing down all the part and I will leave it for the interpreter). Probably I will leave only one part as basso as I stated before.
Talking about the tempi, "Andante Largo" is supposed to be the original, this is why I wrote it, and I understand about the feeling of insufficient contrast. As an arranger I mostly tend to be more close to the original than to interpretate the score and give it a more personal outcome, but maybe it's something to work on.
Also, I will add the original versions of the works now in the original post.