I just used postgres to build my search engine and it also helps with the last 2 questions. Keeping the content context consistent helps with the first. Unscatter.com for example is content shared only in the last 30 days. Helps with keeping my operating costs under $50 a month too.

I wish I had time to mess with it more. Job and life has taken over. My first goal with AI would be to use it to for key word and phrase extraction and also analyzing all the links I pull in hourly to see if there is a larger story I could make visible.