maybe my version of using Native code is different from yours but bugs are present like pictures being dupliacted to library and storage etc .. but I don't think they are bringing in more stuff to bridge the gap.
Native code is any compiled program code that runs without the support of a runtime environment. At this point, that means C/C++. C#, VB.NET, Java and most other high level languages run only with the support of a runtime environment, which is why they aren't native. That is how MS themselves define it and that definition doesn't leave much room for interpretation.
Yes, WP still has many bugs to contend with, just like the ones you mentioned, but they aren't directly related to native code programming. Those bugs reside beneath the API layer within the OS itself. If you can trigger execution of the same code path from a managed application, you'll encounter the same bug.
The feature gap between managed and native code will be reduced over time (I don't know if the two will ever reach feature parity). Microsoft is working on that right now. WP8.1 will make another big step in that direction.
Isn't native code faster.
Microsoft's own documentation on this issue states that the performance advantages at runtime are negligible to non-existent. The one exception is the time it takes to launch an application, where native apps are consistently faster, because they don't need to initialize a runtime environment. However, that advantage can only be reaped by pure native apps with no XML or managed code support whatsoever (very few such apps exist).
The only good reason to use native code (at least at this time) is to simplify app portability (particularly games). That also explains why MS didn't find it important to expose native API's for platform specific features, as it would have defeated the whole point of supporting native code in the first place (portability).