Ok, I see what you're trying to accomplish and why you have Monolith and Looting. Your ability to switch gears with the same set of cards is useful, instead of having to rely on drawing into the right backups. Your design makes much better use out of Echo.
I assumed the main use was for Peer, like most recent storm brews. Any counter on Peer sets them back a lot. If the main use is doubling up on Echo, then yeah, that's a lot more redundancy to push through blue. Because Peer doesn't have the deck restrictions AN does, you can play the full 4 Echo, so then I guess building to optimize Echo is the natural evolution while you still have access to Peer if you need it.
I wonder if that was because of Zirda's dominance more than their fear of it in storm. Players would have gotten used to killing Monolith on sight just in case you were going infinite.
It's much weaker on T2 into a T3 line, but acceleration mitigates this. I can T1 Grid off Rite/Petal, or T2 it and then LED+Echo the same turn. It's much stronger in lines like that. Rituals are worse for you, but what about Tomb?
There's also just the threat of going off fast. Let's say they have FoW. Do they let Grid through banking on leaving 3 mana open to stop your turn 3? What if you have LED+Echo and blow them out that turn? What if they can't afford to skip turns to hold up FoW while you develop your plan? Chances are it'll draw out the Force. If they're on Pierce instead, then they have to counter because they won't have it T3. I've benefited from both sides of this: I've had the opponent let Grid resolve and blown them out that turn, and I've had Grid bait counters when I didn't have it.
Another thing I really like about Grid is its ability to just shut off everything. You don't have to worry about anything they draw in the new 7, including problems like
Stifle and
Mindbreak Trap that slip through Veil.
Ancient Tomb would work in a Monolith build and also help hardcast Echo, flashback Looting, untap Monolith, and play your expensive Wish targets. Have you tried Tomb in RUG (without Ritual and Peer)? It sounds like your structural issues came from being in black, not Tomb itself.
Because you're really heavy on the Echo engine, what's your play against Surgical on Echo? Have you considered
Silent Gravestone as cheap GY protection that also turns on Opal? Gravestone also randomly hoses fast lines from BR Reanimator. That was a SB trick I used in Jeskai Breach to both protect my combo and disrupt decks like that.
Why Study over Looting, even in a fast build? Do you need to cast it off Tropical enough that the blue cost matters more than potential flashback grind?