The problem about Brave not loading pages and having to restart was resolved who knows when, I haven’t got it in like two weeks.
So maybe it was a problem with Chromium, or some feature that was causing conflicts with Chromium and got resolved because something else got fixed or changed, I used to get it twice a day sometimes, but I have been 3days without restarting my browser and everything runs perfect now.
So if you are not using Nightly, you will have to wait for whenever the fix lands, might be a Brave major version or Chromium 115 or something.
About dark mode, it can already be done, and it is better and easier in Desktop, so no reason to wait for Brave to implement it.