This is a very good card, a very good control card imo. However to use the words of the group at large any aggressive opponent will wreck this card. There are plenty of cards which deal with this card very easily.

The main questions are this, is it every book? So honestly is it really any more of a threat than any other?

Sure it turns off Melee buffs, but honestly it will just direct play until it can be removed. This game is a game of problems and solutions, it is about using the spellbook points you have to make the best book for your favourite mage. Any player worth their salt will either take  Altar of Ifernia on the chin and play around it or obliterate it with the hatred it deserves, once it is in play.

So I reiterate my question why is this such a problem, and let me answer that too; it is not. You expect these kinds of play during book building and plan accordingly. "I want to do A, I use B and C cards to accomplish this. D and E Mages/cards give these roads to victory problems, do I chalk these up as bad match ups, or can I use F and G cards to counter these problems?" F and G can be Acid Ball, rust, dissolve, the list goes on.

It is also a well known fact in Customisable games that a pool of players will usually have a (group of) best player(s), that(/those) player(s) will win more games than others using a range of books/decks, usually from the tier 1 pool. Players within the group with them will either stay at the same level of play or get better as they strive to beat the best player(s), competition breeds competitive play at all levels; this ranges from causal to tournament level. This is the same with the new players, it is very rarely that they leave said group due to always losing, but normally they fit right in because it is not just about the game, but the people and the experiences made.

If anything this is a weaker example than the swarm hate that is in nearly every book. However this does not drive people from the game, just they adapt.

Emerald Elk Stave is to swap out for the Dispel Wand so it (Dispel Wand) cannot be dissolved.

It can still be dissolved. To prevent that you would be better with nullify. A clever player will plan timing to take your wand from you, for example as a final quick cast without initiative or a first quick cast with initiative. If it is that important then maybe a spare copy in the book would serve you better, rather than another piece of equipment you do not plan to use?

I imagine that there could be a Dark version sometime, perhaps called Passage through the Underworld (otherwise identical to Divine Intervention).

It would worded quite differently. I would vote that such a spell would also require priority

Also the first turn opening I have been playing with for a different holy book.

Timed versus non timed books are completely different animals. They could even share the same spells but be played using different beats. In a timed game there is always that sword of Damocles hanging over you that you must finish in a set time or risk losing to a time decision.

In my experience these books do not hang about and follow a pattern of Setup/Mana, creatures, kill/mitigate problems. Huge swings of damage are important as, even if they do not kill the opponent then it will affect their ability to win during a "to time" decision. This is why I would say that Restore should be banned in competitive play it focuses a win at timed. Sure I mistyped a value, but the core of the argument is still there. The Priestess can easily swing 19 (10 + 8 dice (avg) + 1) damage on average with a heal and restore. No other mage can do this and thus it is an unfair advantage.

In untimed games then I have no time limit to worry about and my focus shifts so I can get my manas worth out of a spell. Over 4-5 hours you can easily just build an armored shell, where corrode and rust does not affect you greatly. Sure you want to go to the kill but it is at your speed and it becomes a game of poker and chess to outfox the opponent at a leisurely speed.

Ah I see, you made two separate statements there, each with its own line. This said to me that you were making different statements about the single topic, not a continued statement.

Forcemaster - Chant of Rage, target their creature, and indirectly target a Force Gremlin you control. The Force Gremlin is invisible thus cannot be attacked.