Well actually that article doesn't cover your situation well. I am assuming that your video card is sending digital over VGA or it wouldn't work at all. I have had cards that had VGA/DVI so what you are losing by using VGA over HDMI is the audio. Well duh we already know this. However had you been sending an HDMI signal it would include Digital Audio as well. Where as if you use a hokey setup you will have an analog audio signal and a lowish quality one most likely.
Secondly, the amount of energy required would turn your ship into fire. You're better off trying to pin the pieces of space together. With the discovery of the Higgs Boson, we're not too far off from being able to control mass in the same way we control electricity. If that's the case, then you'll probably see experimental nuclear drives pushing the spaceship around.
If you're not worried about losing your family, you can also just freeze yourself and time won't be a problem and it wouldn't really matter how fast you're going. You obviously haven't really thought this out, so I guess it doesn't matter. Even then, at those speeds, you haven't gotten around unknown radiation sources, invisible electrical storms, nebulae that eat everything alive, etc. etc.
Also, running audio/video separately is a thing of the past when everything was an analog signal. Digital Signals don't need to be separated due to the nature of the decoding done by digital signals. Unless your source is of extremely high quality: i.e. FLAC or some other source, it doesn't matter. Having a high quality sound card to transport your sound from won't make a difference between HDMI and a standalone digital audio card when your source sound is like 200kbps. And besides, HDMI can push 10.2 Gbit/s. Unless you have the master source for sound and audio and are running them in like 80 instances, the HDMI will be more than capable of pulling your data through. And even IF you wanted to run your audio separately, you would run HDMI to a receiver anyway to distribute your sound out to speakers as receivers are more and more running HDMI input. So yeah, you're wrong.
You obviously don't understand why audio and video would be run to seperate components but that's o.k. As you say at your level of use it doesn't make much of a difference. Just buy a receiver that does all the complicated stuff for you and forget I ever mentioned it.