All your points can be boiled down to a single point:
They didn't take competition seriously until it was too late. Same can be said about Nokia and probably in the not too distant future it will be Microsoft.
Nokia took the competition seriously, but made a single fatal error: it tried to evolve its low end platform into its high end platform. While that strategy makes complete sense in 90% of cases for market innovation, in the mobile phone industry--which, it turns out, was going through revolution--Nokia should have done the opposite. People often forget that Nokia still controls more than 70% of the worldwide phone market, and controlled vastly more of it in the mid-2000's. In 2007, they had no idea that 90% of industry profits would come from the 30% of the market that they were not focusing on.
You can't really fault them for that, because strategically it makes perfect sense. They regarded the competition seriously but had a flawed approach/response.
That being said, they had a bunch of half-assed hedges against their fatal strategy, like high-ish end platforms such as Maemo, Symbian's advanced versions, etc.., but in fast moving markets with extraordinarily complicated infrastructure/platforms, this approach does not work. You can half-ass evolution, but you have to full-ass revolution.
They realized this mistake fairly early on, but by then it was too late to develop a platform, and full-assing it would have put the company's core competencies at huge risk. So Kallasvuo was fired, Elop was hired, the company moved in with Microsoft, and, eventually, they married.
I think Microsoft has a better chance of creating a more sustainable ecosystem, especially when it comes to having a seamless personal and enterprise experience. I'm talking 3-5 years down the line here.
Meanwhile, I'd be more worried if I were Apple. It will be hard for them to keep-up with the innovation. Especially since there is a flood of new OSes coming like Ubuntu, Tizen, Firefox and more flexible HW platforms.
I am far from an apple fanboy and I use products from all three companies Google, Apple, Microsoft extensively, so I hope it doesn't come out as a bias or fanboyish response.
I honestly think that out of the three companies, microsoft has the worst future prospect. The difference between apple and microsoft products, in my humble opinion is that Apple gives you an experience (however over-priced it may be) while microsoft gives you a product. People tend to remember pleasant experiences for a long time. I don't remember if I ever used a microsoft product that completely blown me away. With Apple I have, several times. The only reason I don't use any recent apple product anymore (except for my three year old macbook) because I seriously dislike their walled garden approach.
I agree with you on the point if Apple can continue to innovate in a post-jobs world. Its hard to say yet and I am not yet convinced with their recent products. Another problem with Apple is that they depend too much on few key people.
On the other hand Microsoft will die a slow death because one of their key market, desktop OS, is soon becoming irrelevant; as people are moving to mobile devices like tablets. And MSFT doesn't have a strong foothold in this market yet. I don't know much about MSFT enterprise market though. But I would guess they were able to be so dominant in enterprise market because of their strong position in desktop market. Will this still be true in the future? I don't know.
They didn't take competition seriously until it was too late. Same can be said about Nokia and probably in the not too distant future it will be Microsoft.