What would a Warlock understand from written spells outside of their class, via Eyes of the Rune Keeper?

This related question asks if you could transcribe a ritual spell to the warlock book via the Book of Ancient Secrets invocation regardless of spell lists, and the answers were generally “yes, but you can’t tell what the spell is”.

This other one asks if you had the Eyes of the Rune Keeper invocation, “could you cast a scroll of a spell outside of your spell list?”, and the answer, using a quote from Crawford, was that you cannot cast the spell since it was out of your spell list (but it did not state if you could actually read the scroll).

By this point, you can probably guess where I’m getting at.

The description of the Warlock eldritch invocation, Eyes of the Rune Keeper:

You can read all writing. You can comprehend any written word or symbol, should it hold any linguistic meaning.

The rules on scrolls outside of your spell list:

If the spell is on your class’s spell list, you can read the scroll and cast its spell without providing any material Components. Otherwise, the scroll is unintelligible.

Can I understand magical literature that is normally outside of my class list if I have the Eyes of the Rune Keeper?

What would I be able to identify from a written spell with Eyes of the Rune Keeper?

Note: I am not asking if I can cast spells outside of my class with the invocation; I am asking if I can understand the nature of the scroll/spell, even if I can’t cast from it.

Related: Can Warlock's Eyes of the Rune Keeper decipher written code?

Is it possible for a campaign-specific magic item to be used outside of the campaign it is from?

I am currently planning to run a game for my family.

Is it possible for campaign-specific magic items to be used (not just carried) outside of the campaign they are from? For example, could Saint Markovia’s thighbone from Curse of Strahd be used in a Waterdeep adventure?

Frequency of cantrips outside of battle

Despite being “at will”, how often can a cantrip be cast outside of battle? For example, how long must a player wait before shooting 2 fire bolts, and is there a limit to how many could be cast or can they just go at it continuously for a day without incurring penalties?

Some Background

I have recently started DM’ing and there’s a few concepts that still elude me, or at least I am finding some trouble reconciling my interpretation of the rules and practical balance.

As I understand it, cantrips can be cast “at-will”. That’s fine inside of battle, but outside of it, things begin to get extremely broken. I have a player whose solution to most challenges is to “fire bolt it”. Is there a reinforced door? A stone wall? A shielded altar? He will just fire bolt it for 8 consecutive hours… Now, on most occasions I have been able to come up with counter-measures, like, bouncing the fire bolts back at him when they hit the altar’s shield, but still, it sounds ridiculous to me that you could just cast continuously for 2/3 of a day if you wished it so, without incurring any penalties… it’s simply absurd on so many levels! And yes, I know you technically could say “I hit it with my club for 8 hours”, and it would be just as ridiculous in my mind that there would be no fatigue, no weapon deterioration, etc…

I have told my player he can cast once every 6 seconds (since that’s the duration of a turn in battle), but I have no idea if that is correct, and it still feels unbalanced.

Can a spell cast outside a primal magic area affect its interior?

The question divides in two possibilities:

  1. A spell is cast outside a primal magic area but the target/place is inside of it. Does it work?

  2. A spell is cast outside a primal magic area but the target/place is outside of it, but the spell’s area of effect still affects part of the area. Does it work?

The example that came to my mind: a fireball cast to explode inside a primal magic area or outside of it, but the explosion still reaches people inside the area.

How do I gain extra feats outside of normal levelling?

I’m new to D&D and new to version 3.5 particularly.

I’m creating a character using the PHB and need to know if there are any means for getting extra feats – perhaps some items or possibly quests?

This knowledge is very crucial for building characters, as two sets (for 7 feats and for 9 feats) differ dramatically.

We are adventuring through Faerun.

The DM says that for a novice, using PHB1, PHB2, Complete Arcana, Complete Divine, Complete Warrior, Complete Adventurer and DMG1 (prestige class section only) are sufficient, but he may for his own needs draw events, rewards and so on from additional sources.

I’m planing to breed Cleric lvl1, Wizard Lvl4, Dweomerkeeper lvl 10 (we agreed with DM to override experience cheat of this class) , Archmage lvl 5.

Three of my feats go towards archmage prereqs, eschew materials, and some metamagic. For others I may get more metamagic or get SLA from Archmage and use maximize SLA on it, or get extremely useful precise shot for not hitting my own companions that are all melee.

Would a level 18+ Champion Fighter recover HP outside of combat?

At level 18 a fighter with the champion archetype gains the survivor ability which lets them recover HP at the start of each turn provided they have more than 0 HP:

Survivor

At 18th level, you attain the pinnacle of resilience in battle. At the start of each of your turns, you regain Hit Points equal to 5 + your Constitution modifier if you have no more than half of your Hit Points left.

You don’t gain this benefit if you have 0 Hit Points.

Does this still apply even if they are not currently in combat?

How to be able to still view Encrypted files on Samsung S9/Android, but not outside of it

I had lost a phone once and I was more upset with the idea of the bad guy having access to my Micro SD memory card/personal data than losing the phone itself.

After getting a new phone, Samsung S9 has a Encryption feature for SD cards, but the thing with this is, it won’t allow viewing of files unless it goes through the long process of Decrypting it on the phone.

I want a way to still be able to access encrypted files on the phone itself, but will require a password to decrypt/view outside of the phone (if the memory card was removed and tried being viewed on a computer for example, that this would not be possible).

Any possibilities?

What determines what type of spell casting focus I may use for a spell I obtained outside of my class spell list?

My intention for this is to understand if I took a Feat or obtained a spell not on my spell list for the class I have, May I use my focus for my class to cast the spell that isn’t on my class?

I’m sorry if the wording is clunky.

Example: 1st level High Elf Cleric, I choose the Fire Bolt Cantrip. May I use my Holy Symbol Cleric Focus to cast my high elf Cantrip?