I'm not sure about in Dark souls 3 but I know in Dark souls 2. I was never soft banned for using Infinite health, mana or stamina. It was just the other things on the trainer such as adding souls, adding stats, infinite item uses (Since there were limited items, the game checked how many you used. So if the game only has 5 items of a certain item the entire run. Yet you used 6. Made it obvious) that caused people to be soft banned.
It could be different this time around, who knows. We will find out when they send out he first wave.
This would awesome
Just push Option 5 while in your stash at a bonfire, moving an item over to the bonfire stash and adding another will allow you to 99 (or max) of that item in your inventory and 600 of that item in your stash.. You can also dupe weapons and armor this way.