Considering conventions and the fact that it will be pretty much impossible to change what C-c and C-x are supposed to mean in Emacs, the answer is that you won't be able to do that. Both have their significant meanings, they're assumed to be there, and modes are supposed to be able to safely assume that these are prefix keys.
Since using Emacs without these prefix keys is pretty much impossible, and you might need to use keys starting with these prefixes with region active, there has to be a way to explicitly use these keys as their intended prefixes.
If you take a look at the docstring for
cua-mode, you'll find this relevant part:
CUA mode is a global minor mode. When enabled, typed text
replaces the active selection, and you can use C-z, C-x, C-c, and
C-v to undo, cut, copy, and paste in addition to the normal Emacs
bindings. The C-x and C-c keys only do cut and copy when the
region is active, so in most cases, they do not conflict with the
normal function of these prefix keys.
If you really need to perform a command which starts with one of
the prefix keys even when the region is active, you have three
- press the prefix key twice very quickly (within 0.2 seconds),
- press the prefix key and the following key within 0.2 seconds, or
- use the SHIFT key with the prefix key, i.e. C-S-x or C-S-c.
If you're pressing keys fast, or pressing these prefixes without an active region, the intended functionality of
cua-mode kicks in.