Super has had a bad schedule from the beginning, this is why the quality of the show is all over the place. The schedule seems to be slowly improving but the fact that Toei is suddenly throwing lots of animators on episodes says they want the show to look better right away.
You're right about the awful schedule it had. It's gonna be hard to find the references, it was all on Kanzenshuu back then.
But they decided to make Super in a stupidly short amount of time.
They had NO plans regarding what would air after Dragon Ball Z Buu - Kai.
Dragon Ball Kai was born because they wanted a new DBZ series, but didn't want to do it without the involvement of Toriyama. When he accepted to do the movies outline, they offered him to do the same thing for a series, which he agreed to. (knowing them, they probably had been asking for years so they jumped at the opportunity)
They decided to make DBSuper after seeing the incredible success of FnF in the theaters, only a few months before the end of DBZ - Buu Kai.
That is insane. Especially with no manga counterpart to base it off. The movie retellings had two purposes, 1) getting rid of Fox's shares for the movies on the same content 2) buying time to get the story developments going.
Now the problem with that, is the fact that Toei is extremely limited, production wise. They launched that new show while literally all of their staff were busy on other shows and tried to make it work, thus the awful schedule. For instance, they had a One Piece TV special scheduled while all staffs were taken, that actually needed to borrow staff FROM DBS. That resulted in the death of art known as "Goku vs Frieza" in the FnF arc.
Why it looks like DBS has a bright future :
- Toriyama isn't getting bored and the work load required is very minimal (a few designs here and there, and he has support from his editors to come up with new stories)
- Several Toei shows ended and their production value was put on DBS
- DBZ licence is stronger than it's ever been in the past 6 years
- DBS is consistently in the top 10 of anime since its launch
It should be good from now on.