What I want:
- Responsive design
- Teal blue/white with a bit of black
- 2-column desktop display, 1-column for mobile
(I've mocked up a design like this already, though it's a bit plain:

- I has a herp derp when it comes to working with Wordpress (I almost broke this blog trying to fix it before -_-)
- None of the 1000+ posts are formatted for mobile; many use tables for info organization, for instance
- I used <p> classes for headings and subheadings in my posts, instead of <h1>, <h2>, etc., and I don't think <p> classes translate on mobile very well :/
So...should I just scrap this Bootstrap layout and just install a premade theme, or would a premade theme face these exact same issues? Do I need to do some groundwork beforehand?