2) Font is too small and light. Make subject font much bigger. The 2nd line is not nearly as important as the title, so title should be much bigger. (your darkmode is better at this than light mode). Personally I prefer Verdana to AppleSystemFont as the latter is very light.
1+2) The posting page has too much vert space between posts and too small font. I'm here for the text.
3) I don't care about icons. They don't help me to decide "do I want to read this posting".
My layout design: https://imgur.com/a/uBPb2pC