First off, Ikuto should have been less obnoxious and more useful. E.g. using his pimp force (and general sanity) to make Machi be less tsun-tsun and more dere-dere towards her sister... or no hot dickings.
Suzu should have made herself taller three years before Ikuto shows up.
Ayane was good, stroking my Saeko Chiba fetish aswell. To me, she had the truest feelings, but was Suzublocked.
Machi should have been tamed over time. Relying more on wits and weirdness than black magic to get Ayane do her chores.
Rin was perfected to her role, Suzu ate her screentime, the glutton.
Chikage should have lost the stupid elephant. God I hated that pink elephant. Oh god she was so adorably perverted, damn Suzu, damn elephant.