[C4thie]

Hey!
Till now I was using original ebook files from bookstores and I didn't modify them. However lately I realized that many of them are not made in the best quality possible, and some books could definitely look better on my device. I also realized that some of them tend to have errors or for example: in one of recent book I bought one chapter had 1mb (!) and was not divided properly.

So I decided it may be good time to take care of it by myself. To make these ebooks look better on my Kindle & avoid errors, to make it working faster etc, etc.

I already learned how to resize book covers to fit whole screen. I "edit book" in Calibre to fix errors. I edit metadata, use polish function, etc, etc. Then I convert it to AZW3 (for my native language ebooks, to add hyphens, with Hyphenate This! plugin), and KFX for english books.
In AZW3 I also justify text and remove colors in styling tab (because some books was annoying with grey barely visible text).
I also change margin settings, to 0pt in left and right (Page Setup).
And I must admit that these changes already make ebooks look much better than before. And I think indexing works much faster (less battery consumption).

BUT!

I'm wondering about one more thing. Fonts. Those provided by publishers often do not suit me and I prefer to use fonts available on my Kindle.
How to get rid of them safely? Without accidentally damaging the ebook?

As I see, when converting, there's option "fonts" in styling tab. However even when I use it, when I edit ebook (after converting), then I see that fonts wasn't removed. It only removes "font-family" from some css, but not all. However maybe it's enough?
Btw, when I edit book, there's also "Manage fonts" and option to "remove selected fonts" and it actually works - it removes all embeded fonts. But is it safe to do it this way?

Which option should I use? Or maybe both are fine?