1. You think MS won't have a tools advantage, lol. MS tools will be better.
2. The 3gb of ram thing is just speculation, rather stupid speculation, full windows does not need that much ram so xbox 720 won't need anywhere near that much.
It can and likely will. This memory is specifically there to avoid swapping to the rest of the main memory. Along with the basic OS services one will likely be running multiple applications which may or may not bloat over time. These applications could literally eat up GBs of memory quite quickly. It's a simple, definite and logical scenario
This is why Tools are important, and nobody is better than MS when it comes to tools. And so far all the insiders have said they have heard that the 720 is easier to dev for.
As for the rest, you have no idea what you're talking about.
Without sources "insiders have said" means nothing
Kinect will not be a mega focus, MS can already tell from the last few years that while it initially was a huge success, it is not selling that well and neither are the games. It will still be there for the people that actually like it, but MS has said time and time again that they are looking to focus more on core games.
Recent history contradicts what you're typing