@Nanabee
The ring is there, just look at the lower right of the character edit screen.
As for your first question, when it says "unbuffed and untalented" what it means is make sure you have 0 buffs on when you are looking at your stats to input. Also, if any of your talents affect your stats (e.g.
Ravenous Dead) make sure to edit them appropriately. The OP shows how to do this (for the above case, just take your Strength and divide by 1.03, and that new number is what you input into the sim for Strength). You do not need to respec in order to input your stats, just understand that when you run the sim, it takes into account your talents, as well as your stats, to come up with your DPS meaning if you hadn't edited your Strength as above, it would do an additional 3% on top of that number (which already includes the 3% from talents).