More notations issues concerning a historical piano score I am preparing for IMSLP

I am reading a score in Spanish which is a transcription of a rare and "lost" piece from the mid 19th century, which I am preparing for IMSLP, and the following notation issues arise:

(1) Are the "v" shaped signs here under the B's, marcato marks? Because if so, they appear to be upside down. I especially am wondering because as I understand it, a marcato is like an accent and a staccato combined, however, the last BbEbGb chord on the bass clef actually has an accented staccato over it, so this begs the question if these "v"s really are marcato marks, and if so, how does playing them differ from playing the BbEbGb chord with the accented staccato?

(2) Even for publication by musicologists, I believe that indicating alternate readings directly on the score is non-standard these days, isn't it? Specifically, in measure 5 of the score, there is a questionable Db, and I assume the Spanish question marks around the natural above it are indicating that perhaps this should be a D natural instead. (Although maybe it is indicating the reverse? That the original autograph score had a D natural but it perhaps should have been Db?) I certainly have noted in urtext editions, that this sort of alternate reading is relegated to the notes. Is it considered non-standard to directly indicate an alternate reading in the main score like this?