Re: Custom HTML Tags, Good Idea?
Try running them through the W3C validator, it'll fail.
No browser is required to "support" them, as far as the HTML standards are concerned, they don't exist. If everyone would be allowed to declare their own tags as they wish, browsers will soon start supporting them out of the box. Perhaps things like a <warning> tag. The browser would then show a warning in the normal style. You think that's good? What happens on browsers who don't support the <warning> tag? What happens when you finally make the warning look good in one browser? In both cases, yes, it'll be messed up. People will rely on it though, causing webpages to become browser-specific (again). As you might recall, that's not a good thing.
The alternative is to keep it the way things are. You can use any tag, like <div> and style it like you want, using CSS. Problem solved.
Besides, ignoring anything else there are two remarks that stand, no matter what.
1. HTML should only be used to express the document structure, not the style. Use CSS for any styling.
2. Why? You wouldn't be able to do anything more than you can now. Is typing <div class="customstyle"> so much more work?
Real programmers don't document their code - if it was hard to write, it should be hard to understand.