There's like ten Dornish plotlines that could be simplified into one character, if they wanted, and lose essentially nothing. But I think the real time saver is.... hang on.

[hider=spoilers from the books kinda]The real timesavers are (1) Tone down Brienne's quest, first and foremost. Ease up on the sparrows, less back-and-forth, boil the whole thing down to one or two revenge-shots for Harrenhal and be done. Then (2) Forget about **almost** all of Mereen. The dragons need to be locked up for about two episodes and then it's *over*. That shit. Goes. Nowhere. Toxic television, skip it all. [/hider]