u/ujujujujui

So I recently bought a used Gaggia Classic 2002 model and spent the last hours trying to clean this thing. I screwed off the shower screen and plate and cleaned those and the portafilter with coffee fat cleaning pills that I dissolved in warm water.

1. Is the portafilter (pic 2) clean enough now?
2. How am I supposed to clean part above the shower plate? It looks quite gross (pic 3).
3. whenever I put the machine in steam mode the steam wand steams a bit with the valve being closed. There is more steam when I open it ofc. Do I need to change the valve?
4. I live in an area with hard water. Is it ok to mix it \~1:2 with destilled water?
5. As far as I know I can regulate the pressure to 9 bars quite easily with this machine. Is there a kind of manual on how to do that?
   Thanks a lot!
   A new fellow Gaggia user

(Second post as I forgot to add pictures before)