Here, watch this series of videos if you haven't seen Metroid Other M's cutscenes and don't mind full-game spoilers: Metroid: Other M ~ The Movie ~ Part 1 - YouTube
Yes, they should continue to expand her character.
Yes, but only to fix characterization problems from Other M.
No, they should focus on Gameplay.
No, her personality is beyond saving.
Here, watch this series of videos if you haven't seen Metroid Other M's cutscenes and don't mind full-game spoilers: Metroid: Other M ~ The Movie ~ Part 1 - YouTube