in the books talisa doesn't even go to the red wedding, she is left at riverrun because robb doesn't want to antagonize the freys further and he wants to keep her safe. There is also the issue of whether Talisa betrayed Robb or not - eventually we learn it was all Talisa's mothers doing, including her feeding Talisa anti-pregnancy drugs so their family gets land and marriages from the Lannisters. It doesn't seem to be a really crucial thing in the books though, so like you said they may change it so Talisa gets killed at the RW or soon after, since dragging in her whole family seems a bit unnecessary.
The Patchwerk removal is interesting, since he was sort of a link to the Drowned God. He was on a ship that went down and was the only (?) survivor, and he probably saw some bad shit in the water that's reflected in his creepy rhymes. I doubt they'll put that backstory on Stannis' daughter, which makes you wonder how much of the Drowned God stuff they will end up chopping out.