-
It’s surprising that you consider the text monstrous! it’s 15px by default, which I think is 1px larger than Flarum. We’re still on the small size in my opinion! If you look around at some news websites (which are optimized for easy reading), the standard is usually larger than 16px (which is the browser default). Many are closer to 20px for articles!
The width of text is also a conscious decision on our part, shorter line lengths are generally considered easier to read Line length | Butterick’s Practical Typography (but of course this can be subjective, we try to land on defaults that work for most people).
-
We have 6 different category page styles to choose from, they have varying amounts of information, and they can all be customized with category images. If you’re an admin you can visit a category page and add images by clicking the wrench
-
It’s possible to build a sidebar nav in a theme, though a little trickier to make it always present. There’s a theme component that does this for topic list pages: Topic list sidebar navigation, though it reuses the dropdown menu so it’s not 100% what you’re after. We have to support sites with dozens of categories, which is why we tend to stick to the dropdown.
it varies… if you want things to be smaller and more compact, that can definitely be achieved with CSS! But sidebars and other additions will need more advanced theming, some of which is covered in the developers guide to themes.