First, Drew Karpyshyn left of his own free will, he didn't slam the door on his way out or anything like that. He just left - after 12 years - because it was time for him to work on something else. And he got replaced e.g. ge was told to go to Austin. This is normal corporate behaviour for firms in the US and Canada. From a European standpoint, it may seem a bit odd, but such is the reality over there.
Second, Hepler is told what she'll be writing - the story, the characters, the backgrounds, or the little tidbits here and there - maybe some of the banter as well. All goes through David Gaider's hands for approval. And then Gaider meets the higher ups including maybe Ray and Greg to discuss the future of the games and how the game story, characters are going to evolve. And she hasn't said, she doesn't care about gameplay, as I see, just that she's not that good at combat and that she prefers to work at creating stories, characters etc. than doing combat. She might have it said it an smarter, better or more toned-down way, though. But the thing is still this: She prefers to work to write stories to be used in games, not to work at the arts or the combat department. Probably the same as I would do...
And for Bioware, the story has always been seen as first, and gameplay as a second. I remember 10 or 12 years back people complained about the gameplay in BG1 and BG2. And yet, people still seem to complain about the gameplay?
Third, there's no new mode in ME3 that lets you skip combat completely. There's a story mode in which combat is minimal and easier than the other modes. However, in the story mode, you can choose settings that range from easy to casul to hardcore to insane.
Fourth, you can have a good story to tell and make combat and gameplay part of this story. And it is no sceret that Bioware for the last at least 8-10 years have been moving into a more cinematic game experience where telling a story is more important than gameplay and combat - the combat on rpg mode and normal in ME3 seems to be just balanced right based on my experience with the demo.
Fifth, Hepler does not write squee anything. In fact, in an interview or a statement she once made, she said something like 'swooping is bad.' And by that she meant that it is much more interesting to write about a character that has flaws and who isn't perfect and reacts to the ordeals of life based on this - like Zevran did in DA:O or like Aveline does in DA2.
Sixth, Hepler doesn't decide whether or not there will be a button to skip combat in the games. However, I do know that many people on the forums also wanted a way of at least skipping, no not the combat entirely, but an option to tone it down a notch or two. And we have it
As you can tell, I'm pleased with this
I, too, play games mostly for the story. And Bioware games tells the best stories around these days. In Skyrim, to compare, you're making the story as you wander along in the game, in ME3, the story has a frame, in Skyrim, you're creating the frame.
Seventh, don't confuse multiplayer with an MMO. ME3 is far from a an MMO. ME3 multiplayer let you play together with 3 other people - online. Basically it is the LAN-party renewed, something a lot of people have been asking anout at the BSN forums for a long time, the ability to play online with their friends.