Run something that doesn't crash. If you run something like ASP, users will be less likely to try to correct errors, because experience will have taught them that your server probably just plain doesn't work. I won't be back. And yes, NT really does have that reputation. Try browsing around for a while, and count the pages you visit that have weird errors and complaints about invalid database entries, and see if you can spot the pattern.
Most users can.
Contrary to popular belief, black text on a black background does not communicate the magnitude of your suffering, or the futility of seeking joy in a meaningless world. It communicates nothing at all, and users are not going to wait around in case you decide to say something later. This is something that seems to be universally loved by novice Web designers, and universally hated by readers. Similarly, try to avoid overdoing your presentation. One page I saw required about 20 minutes of fiddling with browser settings to load.