I'm not sure I would worry if it's only 1mm off from level..
But, if you do want to shim it, you can. BUT!! (But but but!!!!)
Shim only under the stand, NEVER shim between the stand and tank.
For the writing, I would try Windex. Try water and razor blade maybe too if that doesn't work. It should come off somehow.
Nice looking setup btw, can't wait to see stuff in it
