Can't all of that be solved with a message like this:
"Since you are playing in single, cheats are enabled. Note that this map is meant for multi-player and your gaming experience will be heavily influenced by this."
Just an example, you could write anything there.
And if you DO get 1/5's for "i cant kil bos 1/5", then I'm here to remove those ratings.
As a side-note: when I test in single player, I rarely count gameplay as a factor to rate the map, because it is a very personal thing (some people hate it, others love it).
Although I do not expect anyone to do so of course.