I love these -- great job!
If you're still taking votes, I'd love to hear your arrangement of Promising Future from IV, and particularly, version from II's stand out songs Death Place, Phantasy (the quintessential PS melody, I'd say), Secret Ways and Silent Zone.
Different from 1, 3 and 4, I feel that PS 2 has a number of melodies that are more richly mysterious and eerie, particularly in its dungeon crawling themes. I'd love to head some of these represented on a piano in a way similar to how this person re-does Secret of the Forest from Chrono Trigger.
https://www.youtube.com/watch?v=3vgTnT5iKQcGreat work -- I'm looking forward to listening to whatever else you put together. I particularly liked your sensibilities in the Battle theme music.