You know I disagree about the GM. As others have said, (I think Jacko put it best) Theo has been at the helm for 2 WS and the best decade in any of our lifetimes. I'm in no hurry to watch him go to the Cubs or anywhere else.
Manager, meh... maybe. Coaches... probably. This team needed to be ready to play at the beginning of the season (even an average start and they're sitting at 92-94 wins right now) and they weren't.
As for next year, it sounds like we agree on Ortiz. If he takes, say, 8m/yr for two years, he can stick around. Otherwise, I think he's too risky--especially at more years. It isn't his fault, he's had a great year, but it is time to move on.
I think Lavarnway would be mostly a DH, but he COULD catch (more valuable than 1B, which is what Ortiz offers) and he's RH. I suspect it is too early to just give him the position, but I think his bat is the real deal.
What I think about Kalish is that if he can come back healthy he should be the RF of the future. If he can come back healthy, I would think about making him the CF of the future and trading Ellsbury. He is one of the most valuable pieces on this team and could entice another team to move a pitcher.
The biggest problem I see is that there is no good pitching on the market for the forseeable future, and only a handful of elite pitchers on teams that might move them. I think Theo (or the next GM) will need to be really, really aggressive to get one. With Lackey, Dice-K and Buchholz all being question marks, that has to be a top priority IMO.
Also, Crawford was brought here to be what Ellsbury has been this year. Move Ells, put Crawford at the top of the lineup, find another 7th hitter, and have a rotation with another ace-caliber pitcher at the top. Seems like the only way to move forward, to me. Of course, I don't even know who that pitcher would be... so that's a non-starter too.