From my experience since I tried it all and didn't give a damn, I can tell you this so you can play safely.
Use X gold for farming your stage(CM), don't use X Exp unless you fell behind.
God mode you won't need it.
Use X dmg multiplier for farming, stage bosses, companions, adventure, story, promo, Origin of chaos and the blue one, FoC, Closed Mines, Exp.
When I say to.use the dmg for bosses I mean when you are already close to promo but struggling and just need a little bit of oomph to kill it. Use it then
Respect the recommended stages, don't do Ether at stage 200 when the recommended is 340
You can use it for Dimensional Rift also bcs you are capped of DMG done by your promo so if you are Bue Abyss, you won't do more than 15 million DMG so you are safe. As long as you don't do more dmg than the one from the last place, you are good.
In my server last place was 100 and had 29 millions DMG so I could have done 28 and be safe.
Don't ever use X dmg on Dragon Valley and NO RAVE. Is the only one where you have to play normal .
First of all, you will do the most dmg which is weird and secondly, Rave will glitch the robot, if you time Rave when the robot is attacking it will do insane dmg, almost killing the Dragon and you don't want that.
You don't wanna be an Ether player per say and reach top 1 in dmg when you have Ancient Canine slayers or blitzgold lol in guild. You will be noticed.
Also, if you do something sketchy, avoid chatting. This way they won't have the opportunity to report you
Have fun guys coz certainly I did. I am a living memory in my EU4 server, some praise me others hate my guts