Does the party order, left to right at the bottom of the screen, matter? Is the first party llisted on the left up front and the last on the right in the rear? If yes and this is important, can you change the party order?

Like in World of Xeen, the order doesn't matter. Any character can attack or be attacked by any monster that is engaged with the party. Fortunately, everyone can also wear heavy armor.

I don't think you can reorder your characters.