Inferno tactics.

I read that many people use map editors, map viewers, and similar tools.

Viewing a map in an editor, using a map viewer, and similar features are used offline. An offline tournament and an online match are practically two different games. And in online play, cheating is, of course, prohibited, although some individuals do try.
Regarding the topic – I try not to use Inferno only in the Sanctuary faction, but it can be quite effective in other factions. It depends on which faction you are playing against, of course.