I made sure my rock doesn't lean against the glass, and I use a mag float at least 2-3 times a week on all sides.
To hit the back side, I just screwed on a mag float piece to a 4' long piece of plastic I had laying around so I can reach behind the tank and use the mag float. So, I have 2 dry mag float sides (1 by hand and 1 for the plastic thing)
I still have to break out the razor blade every 3 months or so though.
Nope, it's a sebae clownfish and thought I've seen him hanging around the frog spawns, I've never seen him in it. I may get an occellaris clown at some point to see if they'll take.
The skimmer output is flowing on to a piece of mechanical filtration pad/floss. I just have it there to kill the sound and bubbles.