My New Shop!! Yiippeee!

Sorry that you had a bad experience on the Garage Journal forum. There truly is a wealth of info to be had from there.

The thread you reference above is talking about a 2 post lift and leveling issues from right to left. It looks like you're planning a 4 post lift, so not really much of an issue. You should slope slightly back to front for drainage. Maybe 1/8" on 12 or so. You won't notice it at all, but slope just enough to let gravity do its thing.