In the D&D 5th Edition Dungeon Master's Guide, there are two magic items named The Book of Exalted Deeds and The Book of Vile Darkness. In their description, under "Vile Lore" it says that the DM could include magic spells, rituals, curses, etc. As such, I was wondering if I would be crossing copyright boundaries if I were to take the 3.5 Rulebooks for both of these books which completely give all the information a DM would ever need for that "Vile Lore" optional rule and translate them into 5th Edition compatible rules.
I will probably do this regardless if only just for my own benefit as a DM, but...
Am I allowed to distribute this translation of rules to other people for free, for donations, or for profit?
Am I allowed to create an entirely new set of 5th Edition compatible rules for something entirely new (such as a Neutral version of those books) and distribute in the same way?
I would likely be using Chapter 9 in the DMG, the "Dungeon Master's Workshop", to balance the 3.5 rules into 5th Edition gameplay.
I'm aware of the Open Gaming License, but I don't know what it means for what I want to do. It seems to say that I can design all of this, publish, and sell it using 5th Edition rules.