I also agree with a lot of what you’ve said.
There are a few things though that already work:

• Infinite scroll: when you click on the cog wheel (propably on the top right corner) you can enable infinite scroll. And a few other options, which I love
• Formatting: I think this just has markdown support with lists, headers, etc. However I just noticed that all headers are equally large
• /sub as main: you can set the default site that is shown to you, to your subscribed posts. This is however not in the cog menu, but in your personal settings