For ramp, I'm trying out Tithe and Gift of Estates. Low CMC, multiple lands, and in Tithe's case it's a one drop instant.

Check my profile for one of the best G/W Selvala decks on the site and hopefully my list can give you more inspiration with yours going forward. I personally hate the glass cannon all-in combo build you are playing because it lacks the protection you need in cEDH pods but I will however say that the deck is far from bad it's just more dangerous than running her as an Adaptive Stax Combo build.

Enivid
I appreciate your concerns and suggestions for my build, and I very much have considered a more stax-style build. I have found success with Armageddon and Static Orb, but stax is also not great in my personal meta. I have found that there is enough redundancy and protection for my build to work very well- often for my opponents it is Toxic Deluge or bust. I think that when/if I can afford cards like Mana Crypt and Mox Diamond, the all-in build will be much more favorable to the stax one.

Also, the Selvala alter on your deck is quite excellent.

WanderingSpirit
The problem with those cards is that they don't actually ramp, they just find land drops, which isn't really a problem with this deck. If they put the land directly on the battlefield, I would consider them.

@FroggyTroller. That's fair. The other issue I think I might run into is that they don't put anything on the battlefield. One pro to them is that they'll help you thin the deck and hit better parleys, which is why I'm trying them out.

On the whole I really like the list. I run a much more casual version of Selvala but it's nice to see more optimised lists.

A few recommendations I would make though:

• Dryad Arbor and Scattered Groves are too slow. While sure they work nicely with Arbor Elf and the two rangers, neither facilitate a turn two Selvala. Mana Confluence and City of Brass both feel more consistent here.

• have you considered Heroic Intervention as another combo protection piece?

enpc
I was likely going to cut Scattered Groves soon anyway. You should read what I wrote about Dryad Arbor in the notable inclusions section, because I feel that it is had earned its spot.
As for Heroic Intervention, it has been on my short list for a while (I just forgot to put it in the maybe board, so thank you). The only problem is that the most common sweeper in cEDH (or at least at my local meta) is Toxic Deluge, which doesn't care about Heroic Intervention. I think it can be very helpful just as more protection for the combos, so I might try it out.

It's a tricky one. While I don't disagree with any of your points, I do know the drawbacks of summoning sickness with it (I run Dryad Arbor in a Saffi Eriksdotter deck, it's different but similar enough). You do run both Concordant Crossroads and Thousand-Year Elixir which can negate that effect, however I do think that missing out on a turn two Selvala might be enough of a drawback to not run it.

Also, I have had good results with Cloudstone Curio as a combo engine enabler. It gets dumb when you have a haste enabler and two mass mana elves, but is also really good with Paradox Engine.

Another card worth considering is Mirror Entity. It can fill the same roll as Shalai (from your backup win condition description), creates a combo with Wirewood Symbiote (makes symbiote an elf by paying 1 and then returning it to untap a mass mana dork) and also helps protect against Toxic Deluge which you mentioned. Just a thought.

enpc
Those are some really good suggestions, I think I'll try Cloudstone Curio out. The one problem with that is simply that Enlightened Tutor is the only artifact tutor in these colors, and there are already a bunch of important artifacts, such as Paradox Engine, Static Orb, and Staff of Domination. As or Mirror Entity, I just don't think I'll be able to find room.

You keep Dryad Arbor because you can play T1 GSZ for X=0.

Cuts I would make are Elvish Visionary, Harmonize, Seeds of Renewal, 2 Forests. This will let you slot in more removal, another combo package, Noxious Revival, Sensei's Divining Top and possibly other things. You do not own all fast mana rocks or anything like that but your commander is pretty much all you will need for the most part. Joraga Treespeaker is also not very good.

Enivid
Sensei's Divining Top was already in the deck. As for the cuts, I don't think that I can cut Elvish Visionary or Joraga Treespeaker. The deck needs a critical mass of elves for cards like Priest of Titania to be effective. Harmonize can probably be cut, and Seeds of Renewal has constantly impressed me. I really like having Regrowth type effects, so I might try Noxious Revival.

Have you tried adding an Altar of Dementia so you can mill people out, then force a draw with your commander during any automatic shuffle effects? It's a good alternative wincon if combat damage won't work.

Sweepea38
I would suggest reading the primer I wrote in the description - this deck doesn't win through combat damage. It wins through a plethora of infinite mana combos that each allow you to activate Selvala, Explorer Returned an arbitrarily large amount of times. The win conditions listed work well, as well as have other purposes in the deck, so Altar of Dementia has no place in this deck.

I've found that something people overlook with Selvala is the idea of drawing your opponents tends to be perceived as a bad thing. In my experience, the people I play with who have properly constructed decks tend to answer each others cards, even if you allow them all to draw you're drawing them into answers for each other too. So no one tends to get too far ahead, even when they are all seeing more cards. I tend to also run Kismet, Root Maze, Orb of Dreams and Blind Obedience type effects to reallllly slow the game down until I'm ready to pop off.