I believe it would be interesting to have the option to isolate the graphs in the Dopesheet, thus eliminating the duplicated interface that exists in both editors.
[Suggestion] Isolate graphs in the Dopesheet
I'm not sure what you mean by isolate?
You can uncheck Image removed due to the lack of support for HTTPS. | Show AnywayRows in the graph settings (upper right here):
But this way, there's no way to isolate the rotation, translation, and scale graphs, the small dots that are in the Graph Editor interface but not in the Dopesheet.
Ah I see. I wonder if we allowed hiding Rows in the dopesheet would help?
Possibly related, we plan to have 2 ways "sync". Currently we have a "graph-centric sync", where the dopesheet shows only rows shown as curves in the graph. It would also be nice to have a "dopesheet-centric sync" where the graph shows only the curves for the rows or selected keys in the dopesheet.
Yes! Those would be great options for those who work with the Dopesheet and Graph Editor in a sync way like me. I find the option to omit Dopesheet Rows interesting, so I would only have the Rows from the Graph Editor, making the interface cleaner 
OK! We'll add the Image removed due to the lack of support for HTTPS. | Show AnywayRows checkbox to the dopesheet settings in 4.2.10-beta. Looks like:
Note when the dopesheet and graph have their left edge aligned, like in my first screenshot in the post above, care is taken to synchronize the timelines in both views, so the keys align and both views scroll horizontally together. In that case hiding the rows doesn't gain you any horizontal space. Maybe we shouldn't align the keys unless both views have the same setting for Rows.
Awesome! Thank you for taking this suggestion into consideration for the next update!