You should stop the allen key from spinning then crank down on that nut as tight as possible (there will be a torque value but I cba to go to the shed to dig up the haynes to check)

Was the previous car on 13s? I'm going to guess not and thats where the visible difference comes from. -30 on standard KYB's on 13s and that looks about right to me.

Your first picture under the car - secure that brake hose grommet before it gets caught on something! It looks like you/previous owner has crushed the locking tab slightly, should be easily bent back open to squeeze the grommet back in.