Technical SEO still is a very valid optimization. Making sure you have all the relevant tags, a good structure, fast loading pages etc.
Just focus on accessibility and standards.
Hmm. I never would have added Schema.org support unless there was an SEO reason.
Yeah. If you solve accessibility you generally solve SEO as a byproduct. Mainly because accessible sites are easy for machines to parse.
Thinking about SEO too hard sucks, but having a site that nobody can find (even when they already know about it and are specifically trying to find it again!) sucks even more.