Hey glad to hear that 🙂
Regarding Kodi+Squeezelight simultaneously – you could use the Raspbi’s HDMI for Kodi and one of the IQaudIO or Hifiberry soundcards for Hifi. The DAC(+) versions have standard RCA females for your amp!
But wouldn’t Kodi on your Raspberry throw you even further away from your SD Card Write Protection plans? So far they are working on a solution for Squeezebox and Squeezelite but I’m not so sure if that’s possible for Kodi.