Impressive! For anyone looking to do something similar, but in Sublime, I can recommend the LatexTools[0] plugin, which gives similar live previews of math mode.
I'd never considered embedding figures from Inkscape though.
I also decided that I wanted to keep lecture notes in LaTeX, and the best advice I have for anyone is to just practice. Start from LyX if it helps, but just make sure that you grind down the rough edges. It takes a long time, but like many skills that are worth learning, it takes lots of effort but the payoff is worth it.
Start from LyX if it helps, but just make sure that you grind down the rough edges.
Fully enough, I would have exactly the opposite recommendation: Start by writing LaTeX out manually, then move on to LyX when you have a good understanding.
This is due to a combination of (1) needing to already know about LaTeX features before you can know to look for them in LyX (buried in menus or whatever) and (2) although LaTeX errors are much rarer when you're using LyX, when you do get them they're often really confusing ones. I'd say that using LyX requires greater knowledge of LaTeX than using LaTeX directly, just applied less often.
The benefit of LyX is not that you avoid needing to know about LaTeX. It's that you don't have to see it when you're editing your content. Equations with a lot of subscripts and superscripts come to mind; anyone who claims that it is easier to find and fix mistakes in a nested superscript in the raw LaTeX rather than just clicking directly in rendered representation and fixing it in place is, frankly, lying, if only to themselves.
I also decided that I wanted to keep lecture notes in LaTeX, and the best advice I have for anyone is to just practice. Start from LyX if it helps, but just make sure that you grind down the rough edges. It takes a long time, but like many skills that are worth learning, it takes lots of effort but the payoff is worth it.
[0]: https://github.com/SublimeText/LaTeXTools