to get file size down try download
k-lite codecs - full version. then when you are using a compressor use 'X-ViD MPEG-4' or even try a few others.
i used to use 'indeoŠvideo5.10' but i think it needs to be a 1.33 aspect ratio to work. setting the compression quality to 100 will make the file larger, but the quality is better. for the X-viD i just leave the settings as they are.
3ds max would generally be considered to be better than cinema4d, but i've seen some good stuff done with cinema4d.
drivers are your best option to make cinema4d run faster. browse your video card manufacturers website and see do they offer anything. the help files might offer some insight to driver setup as well.
i always use openGL display drivers rather than direct3d.