I admit I don't understand ED's very well, but "add and substract" approach doesn't make sense to me. Why would you even do a spread if cards cancel each other out - why not just pull one card that actually tells what's left in itself?
However, I do get the idea of weighing the elements and seeing how compatible they are. Cups can water down the Wands and so on. However, I think in balanced life all of the aspects are needed and I don't think the weighing necessarily means "take out something" or discount impacts. It's more about seeing different angles of the same issue and different matters or emotions that all play a part.
I don't think you need to use either, EDs or reversals. Everyone needs to develop a style that works for them. If you get clear messages without either, then there's no need to add something that just confuses you. If you struggle with understanding the cards, then maybe pay more attention to the basics and focus on figuring the suit meanings and number meanings with absolute clarity instead of adding extra levels at this stage (or ever?). There's not one right way to read tarot, you'll find your own, even if nobody else does it the same way!
But then again, I read with reversals because that works for me and haven't really delved into this topic of EDs....