Minimal theme. Feedback

Dear all,
This is my first post in the forums and I am very excited to be a part of that incredible community !
Intro
Recently I decided to get into web design and web dev and I started from the basics – HTML, CSS, JS and PHP. Seeing that WP is such a big part of the web I want to be familiar with the processes involved in creating a theme, so naturally I navigated to the WordPress codex.
Initial idea
After some reading, I got down to it and tried to develop a very, VERY basic theme which would include the fundamental procedures to get data from the database and show it on the page. My prefered way of learning is to dissect existing projects, so I opened the underscores theme and the twentyX themes and tried to understand and replicate their functions.
Minimal Theme
So in the end I managed to get the content to show using a very basic approach and a very dirty one (assembling everything in the ‘index.php’). I do understand the concept and importance of templates, but to make it easier for myself I like to put everything together, so I could more easily get my head around it.
The Theme – GitHub
Questions

1. Are the functions and structures I’ve used the proper ones to use when creating an up-to-standards WordPress theme?
2. If I put all the bits and pieces in the appropriate templates (keeping the code structure relatively similar) and I get down to create the styles and scripts for all the sections and functions, would that be considered a theme that can be used in commercial and personal projects?

Thank you for your time !
Vasil