How long do the temporary HP gained from the Aberrant Dragonmark feat last?

The Aberrant Dragonmark feat states:

You learn that spell and can cast it through your mark. Once you cast it, you must finish a short or long rest before you can cast it again through the mark. Constitution is your spellcasting ability for these spells. When you cast the 1st-level spell through your mark, you can expend one of your Hit Dice and roll it. If you roll an even number, you gain a number of temporary hit points equal to the number rolled.

How long do those HP last?

Any way to cast dragonmark SLAs in a rage?

Pretty obvious dual to this question, but now for (dragonmark) spell-like abilities.

While raging, a barbarian cannot use any Charisma-, Dexterity-, or Intelligence-based skills (except for Balance, Escape Artist, Intimidate, and Ride), the Concentration skill, or any abilities that require patience or concentration, nor can he cast spells or activate magic items that require a command word, a spell trigger (such as a wand), or spell completion (such as a scroll) to function.

Spell-like abilities require concentration, though obnoxiously they don’t just come out and say it. Instead we have this:

Spell-like Abilities

[…] In all other ways, a spell-like ability functions just like a spell: […] It is possible to make a Concentration check to use a spell-like ability defensively and avoid provoking an attack of opportunity. A spell-like ability can be disrupted just as a spell can be.

The spell-disruption mechanics are all about your concentration on the spell being disrupted, with Concentration checks made to maintain your concentration and complete the spell despite the disruption.

Dragonmarks are feats that grant spell-like abilities, and since there are a number of feats that tie dragonmarks in with action points and those are something my rage-cycling build has in great quantity, being able to cast them while raging would be very effective.

There’s an argument to be made that rage also says “He can use any feat he has except Combat Expertise, item creation feats, and metamagic feats,” immediately after the first quote above, so you can use spell-like abilities from feats. But dragonmark feats aren’t themselves spell-like; they just have the effect of granting a spell-like ability. That is, I might buy this if the dragonmarks said “This feat is a spell-like ability,” but instead they say “You gain the use of […] one spell-like ability.” So I consider this dubious, and for the purposes of this question we’ll assume the DM doesn’t go for it.

Righteous Wrath is another one that sounds like it might help but then probably doesn’t: though it says “While raging, you retain clarity of mind unusual among barbarians,” it doesn’t go on to describe that how far that goes—and the examples it gives are all things barbarians never had any problem with in the first place. There’s no suggestion that it goes as far as allowing spell-like abilities—and at least one prestige class that requires Righteous Wrath has “You can cast this class’s spells while raging” as a specific class feature, so we can be pretty sure it doesn’t go as far as allowing spellcasting.

Finally, there’s the rage mage’s spell rage and the Rage Casting feat, which allow casting spells under certain conditions. Spell-like abilities are not spells, however, and it’s not at all clear that those features should apply here. Normally we would expect spell-like abilities to be separately listed if they were to be included. The description of spell-like abilities does say “In all other ways, a spell-like ability functions just like a spell,” but in reality this is a problematic description because there are so many ways in which spell-like abilities don’t function like spells. (It would be more accurate to say that a particular spell-like ability functions quite like the spell that it is “like,” excepting that it’s a spell-like ability with all the differences that entails.) In any event, the restrictions on both spell rage and Rage Casting make them really poor choices for my goals.

So, without making assumptions about these things being interpreted generously, does anyone know of a way to activate a (dragonmark) spell-like ability while raging? Tricks to exit the rage and re-enter it are not answers; I want to cast the spell-like ability while raging.

E6 is preferred; Epic is not allowed at all. Otherwise, any Wizards-of-the-Coast-published 3.5e materials, as well as 3.5e issues of Dragon and Dungeon, are acceptable. Third-party material, regardless of its licensing status, and homebrew material, regardless of its quality, are not acceptable (I am already aware of options that fit the bill from those categories; the point of this question is to avoid that). The form of the option doesn’t matter: feat, class feature, magic item, spell, whatever. I’d prefer not to have to multiclass for it but if that’s a way to do it, I want to know.

I’m not really looking for shenanigans; I’m hoping to find something that just says “you can use spell-like abilities in a rage,” or “you can use dragonmarks in a rage,” or something. I guess there could also be “you can concentrate in a rage” would probably get us there, or get us there in combination with forms of spellcasting during a rage, but I’d want to see the case pretty fleshed out for that because it gets into the weeds a bit.

I may accept RAW shenanigans, but only if they’re particularly air-tight and require neither DM assistance out-of-character, nor NPC assistance in-character. In short, please avoid anything that starts going “ask your DM to accept this dubious interpretation that might be there, if you squint.” Greater uses of wish and stuff like that are right out.

Is it possible to qualify for a Greater Dragonmark in E6?

I’m considering running an E6 game in Eberron, and I’m curious if there is some way to qualify for the Greater Dragonmark feat.

Skill Beyond Your Years and Primary Contact can let me reach 12 ranks in a single skill, but the feat requires 12 ranks in two different skills. I’ll likely houserule it, should there not be a way to reach it, but I’m curious if anyone knows of another way to reach 12 ranks in a skill in E6 (or some other way to acquire the Greater Dragonmark feat).

Can the cantrips gained from the Dragonmark feat be cast multiple times?

The Dragonmark Feat from Unearthed Arcana: Eberron says:

You gain the ability to innately cast spells and cantrips, as summarized in the Dragonmark Benefits table, using the spellcasting ability listed under the Ability column. You cast each spell at its lowest level. Once you cast a given spell this way, you must finish a long rest before you can cast it innately again. You must still expend any material components.

Every dragonmark gives the character access to a first, second and third level spell, as well as a cantrip. The second and third level spells can only be cast if the character is of high enough level (, 5th and 9th, respectively).

Usually you can cast the cantrips you know infinitely often. But the way this feat is worded seems to imply, that the cantrips gained from dragonmarks are treated exactly like the other spells, which means their use is limited to once per day. I’m am not sure if I interpret this correctly, if this is intended this way, or just worded weirdly.

Eberron Mark of Making Dragonmark Variant Human

I am confused on how to apply the dragonmark variant on a human in Eberron, specifically the Mark of Making from the Wayfarer’s Guide to Eberron.

Do the dragonmark features (pg 101) completely replace the variant human set (ASI, Skill, Feat), or only the Ability Score Increase of the variant human (e.g. you still get a Feat and a Skill)?