Does an Artificer’s Magic Item Savant and a multiclassed Thief Rogue’s Use Magic Device allow them to benefit from a Rod of the Pact Keeper?

The Artificer’s Magic Item Savant feature states the following:

At 14th level, your skill with magic items deepens more:
• You can attune to up to five magic items at once.
• You ignore all class, race, spell, and level requirements on attuning to or using a magic item.

The Thief Rogue’s Use Magic Device feature states the following:

By 13th level, you have learned enough about the workings of magic that you can improvise the use of items even when they are not intended for you. You ignore all class, race, and level requirements on the use of magic items.

Rod of the Pact Keeper states the following:

While holding this rod, you gain a +1 bonus to spell attack rolls and to the saving throw DCs of your warlock spells.

In addition, you can regain one warlock spell slot as an action while holding the rod. You can’t use this property again until you finish a long rest.

Since these features allow an Artificer or a multiclassed Thief Rogue to ignore “class” requirements when using a Rod of the Pact Keeper, would they ignore all instances of “Warlock” in the text and benefit from the general bonus to spell attack rolls and saving throw DCs, and be able to regain one spell slot?

Related questions:
1. What requirements does the Artificers Magic Item Savant feature ignore?
2. Does an Artificer's Magic Item Savant and a Thief Rogue's Use Magic Device allow them to benefit from a Holy Avenger's 30-foot aura?

Does an Artificer’s Magic Item Savant and a Thief Rogue’s Use Magic Device allow them to benefit from a Holy Avenger’s 30-foot aura?

The Artificer’s Magic Item Savant feature states the following:

At 14th level, your skill with magic items deepens more:
• You can attune to up to five magic items at once.
• You ignore all class, race, spell, and level requirements on attuning to or using a magic item.

The Thief Rogue’s Use Magic Device feature states the following:

By 13th level, you have learned enough about the workings of magic that you can improvise the use of items even when they are not intended for you. You ignore all class, race, and level requirements on the use of magic items.

Holy Avenger states the following:

While you hold the drawn sword, it creates an aura in a 10-foot radius around you. You and all creatures friendly to you in the aura have advantage on saving throws against spells and other magical effects. If you have 17 or more levels in the paladin class, the radius of the aura increases to 30 feet.

Since these features allow an Artificer or Thief Rogue to ignore “class” requirements when using the Holy Avenger, would they gain the benefit of the 30-foot aura?

Furthermore, since they also ignore “level” requirements when using the Holy Avenger, can they benefit from the 30-foot aura at 14th and 13th level, respectively?

Related questions:
1. What requirements does the Artificers Magic Item Savant feature ignore?
2.

How does the spell “Extract water elemental” interact with the energy substitution class feature of elemental savant?

Basically as the title states.

The elemental savant energy substitution states that any damaging spell of a certain type is converted to a chosen type (in my instance, fire).

Will this spell instead extract a fire elemental somehow if the creature is slain? Or will the substitution not take place since the damage of the spell deals is untyped?

Spell in question: “Extract water elemental” Spell compendium Page 86

Prestige Class Elemental Savant -> 3.5 Complete Arcane page 32-34 Class feature in question: Elemental specialty

What is the correct interaction between the spell and the mentioned class ability?

What are some items that the Artificers Magic Item Savant feature allows them to attune to or use?

The Artificer’s Magic Item Savant feature states:

[…] You ignore all class, race, spell, and level requirements on attuning to or using magic items.

Class and race requirements are relatively intuitive and since an Artificer would already be able to cast spells they can already attune to items that require you to be a spellcaster. But what about using a spell scroll for a spell that is not on their spell list? Additionally, are there examples of items with spell and level requirements that an Artificer otherwise couldn’t attune to?

How does an artificer’s ‘magic item savant’ interact with spell scrolls

Does an artificer’s magic item savant allow the artificer to cast a spell that is higher than he can normally cast from a spell scroll without making an ability check to cast it? Magic item savant reads:

“You ignore all class, race, spell, and level requirements on attuning to or using magic items. I already know that a spell being on your spell list is a normal requirement to cast a spell, and this requirement would be removed by magic item savant.

What is unclear to me is that, the spell being a level you can cast normally is required to cast the spell normally without using an ability check. Is this considered a spell requirement for using the item without an ability check?

How does the Quick Study exploit work for a School Savant Arcanist?

I have an arcanist character with the School Savant archetype, which allows me to prepare an extra spell per level of the chosen school (Air in my case) but requires two preparation slots for a spell of the opposing school (Earth for me).

I also have the Quick Study Arcanist Exploit which lets me swap a prepared spell for a different spell in my spellbook.

The interaction of quick study with these school spells are not exactly clear. For example:

  • If I choose to replace a specific Air school spell that I prepared, am I restricted to choose another Air school spell as a replacement?
  • Can I replace a normal spell with an Earth school spell, thus bypassing the need for 2 “preparation slots” (or do I need to replace 2 spells perhaps, or something else)

So how does replacing prepared spells with Quick Study work when both specific school spells from School Savant and other spells are involved?