I dropped Akame too once it hit anime original. But I just remembered that you dropped Twintails pretty quickly, so that's one.
Looks like you ended up dropping Amagi too, so that's actually two.
As for Inou-battle, if you do decide to drop it I'd probably at least get you to watch a 3 minute scene from an episode of the show that surprised a lot of people. Also, Andou turns out to be one of the more
emotionally intuitive harem MCs I've ever seen. Lastly, the powers are roughly 2% of the episode content.
I highly doubt Terra will make your cut, though the rest of your "I think I could possibly not drop these" about lines up with my expectations. I haven't started Shingeki myself (nor Shigatsu, sue me guise) but:
Fate - so much budget
Nanatsu - wonderful
Shirobako - repeating myself again - PA Works making up for Glassshit with a legitimately interesting and fun premise
Haven't watched the rest of that list myself.