1. Body text has the contrast ratio of 7.52 under WCAG 2.0 standards (https://contrast-ratio.com/#%234a5568-on-white) which is within the optimal range for legibility. On paper, the text is 100% black. On the screen, that can be too much, so I used grays. Labels are lighter because I wanted to treat them as supporting text, not main.
2. This is primarily for the Web. So, HTML/CSS. I didn’t know about LaTeX before, interesting.
3. It’s free, and you can modify it, maintain it, etc. The only restriction is that you can’t use it for commercial purposes (e.g., page builder). More info here https://github.com/WebPraktikos/universal-resume#license