As far as I am aware (I may be wrong, but I am pretty certain that I am correct
), the C++ redistributables are required for Windows to function, and the .net framework is required for a few odd and slightly sideline parts of Windows to work. This is why you can never quite uninstall them. If you try, the majority of it is removed, but a few core parts are left over for Windows to function. There is no way to uninstall these final parts. Not one way (apart from deleting the files over a reboot, after removing Windows Resource Protection from them, and anyone who does that deserves whatever they get...)
However, here is some information which I do know:
If you are being offered updates through Windows Update for these products, it means that you do have them installed. To remain secure, you MUST install these updates. Failure to do so will leave an old and insecure version of these products on your machine, which only leads to one of very many possible bad things (viruses, trojans, keyloggers, identity theft, elevation of privilege, even a remote backdoor, etc. etc.) These things exist. To protect yourself, you MUST install all non-optional updates from Microsoft through Windows Update. They are being sent to protect you, please don't hide or ignore them!
redistributables are packages for clients for you to have installed, and are not the developer packages. Programs which required them (most programs require one or the other) install them. So, if you have these products installed, and you didn't manually install them, it means that some program has, ergo uninstalling them will break that program!
So, my advice would be to leave well alone, and keep on installing the updates (and just some random snippets of information, although the updates for those pacakges are usually about 11.5MB, the developer package security updates often reach multiple hundreds of MB, and .net 4.5 looks to contain full .zip support - finally!, although you will struggle to find online documentation for that at the moment)