I would like C to have a native String type, and the primitives could be function pointers, replaceable in those cases when custom handling is needed (e.g. inside kernel). Object Pascal is sort like that.
D has this. A lot of people assume that D is just C++ with some GC and some improvements, but it's really more like C with GC and some improvements -- including a native String type.
There's also a string module in the standard library that includes a lot of convenience methods, including ones for interoperating with C and for working with Unicode[1].
For someone like me with a background in dynamic languages like Python and Lua, as well as some background in C, D was a great fit. Unlike when I started learning C++, D felt like a very natural extension of C to include GC and lots of modern language features.
Lamentably, not many people are interested in D, and so aren't yet a lot of third-party libraries, and many of those that are abandoned. But the core language and standard library are great, and there's a nicely growing and incredibly fast web framework (vibe.d). And Facebook has started supporting the language. So hopefully it will start seeing some growth.
I've gone down this route of thinking many times. Inevitably, as soon as I think of all of the features that I would want in C, I simply end up with a language that's not C any more... for precisely that reason. C isn't that kind of a language; it's a high-level assembly language and little more. Most of the things that C is lacking, it is by design, because of performance reasons and/or need for fine-grain control of the machine.
As another respondent mentioned, there are other languages that fill that need (C++, D, Rust, Nimrod), basically all of the systems languages that are designed to do C's job easier and safer (but probably not faster).
