well... interesting... but i don;t think you offered enough information on this methodology ... I'd go for BEM for css, its usefull when you use sass or less, it keeps your classes organized. But DRY on html... so you;re telling me i should make a template for every element i need on a page? NO! i won't do that. i don;t want to make my application harder to read/modify. But i think this DRY thing is usefull but you have to determine what arhitecture your application will have before using it.
NOTE: i know this isn;t important, but, when using ems or rems, write the fallback for them in pixels, just for older browsers, antic ones and maybe safary