Pretty neat idea, though I do have a number of critiques...
Firstly: It's "poring over", not "pouring over"
More importantly, Critique #2: I really feel like this should be like the Alchemist: a casting class that does not require any preexisting casting capabilities to enter. There's an obvious parallel in style between scrolls and elixirs (both being items that give you a one-shot spell effect), and Scroll Casting is really geared more for use by noncasters
(or at the very least characters with less focus on casting, lacking a full 1:1 casting level and with a greater Crafting bonus than Spellcasting). Requiring that only casters can enter the class significantly diminishes the utility of the Scroll Casting feat that's required for entry to begin with.
Of course, this would be tricky to pull off alongside giving the Scribing B/M/S feats. For one, fitting the whole chain in along with the requisite casting ability at level 1 would be tricky. For another, going by the Alchemist, the spellcasting ability granted should probably be limited to a single school, which in turn would limit your ability to scribe scrolls. However, there are ways to work around this.
Critique III: Ink-Saver is pretty meh. The weight reduction on the first grade is too fiddly to really worry about, and the second grade is nonfunctional as-written (Crafting checks don't have DCs; they have a Complexity that determines if you can even try, and then a scaling output based on your check result). And it'd be fairly pointless to reduce the Complexity at that level, since at that point you should be able to make 5th level and lower scrolls just by having max ranks in Crafting and a decent (+3) Int score. And even 6th and 7th level scrolls are in reach by then if you've invested a bit more in getting your Crafting bonus up (Enlightened Crafting, Skill Mastery feats, a higher Int, relevant Studies, etc.). The only reasonably interesting thing across both grades of Ink-Saver is the one-handed scroll use.
Critique D: Words of Command has some sloppy wording. But I'll come back to this in a little bit, because:
Critique the Fifth: Tattoo Scripture is pretty neat, but it seems a bit odd to be an immutable part of the class. Tattooing isn't necessarily something that will always fit with every concept.
My proposal would be to take Words of Command and Tattoo Scripture and adapt them into some of the options in a a list-of-choices ability you can select from at level 4, 6, and 8 (combining the E, F, and G slots), a la the Deadeye's Sniper ability.
Final Critique: The gamebreaker feels a little off to me. It certainly has the potential to be quite potent -- you can have at-will casting of a 7th-level spell, which is definitely pretty nuts -- but that potency comes at a cost of most of your spell points. Essentially, the gamebreaker pushes you to pick one really potent spell to spam all scene, which is a bit out of whack for the general feel I have of the class. The class overall suggests more of a clever, collected, planning-ahead type, more of a "library of options for all occasions" generalist rather than a "hammer away with one thing over and over" specialist. The gamebreaker is definitely most effectively used for the latter purpose, though.
Perhaps something more like simply letting you cast a scroll without using it up X times per scene/session/adventure would be more fitting?
Here would be my proposed revamp of the class:
campaign quality, Scroll Casting feat, Crafting 6+ ranks, Int 13+
<Other class features & core ability same as yours>Way of the Pen:
At Level 1, you may purchase ranks in the Spellcasting skill, learn Artifice, Seals, and Word spells, and cast Level 0 spells you know. Also, when you fail a Spellcasting check to cast a spell of these Disciplines, no spell points are spent on the attempt.
If you already possess this ability from another class, you instead gain an additional Spellcasting feat.Scrollmaster I:
At Level 2, you gain the Scribing Basics feat, and your Caster Level when casting from a scroll is equal to your Career Level -1.Scrollmaster II:
At Level 7, your Caster Level when casting from a scroll is equal to your Career Level, and you may scribe spells you don't know even without a reference. The Complexity of a scroll you create of a spell you neither know nor have access to is increased by 5, and the error range for checks to cast such scrolls increases by 2.Circle of Power:
At Levels 3, 5, 7, and 9, the maximum level of spells you may cast increases by 1 (e.g. from Level 0 spells you know to Level 1 or lower spells you know), to a maximum of Level 9.Bonus Feat:
At levels 4 and 8, you gain an additional Gear or Spellcasting feat.Scribal Visionary:
At levels 4, 6, and 8, you may choose one of the following abilities. Each may be chosen only once.
- Arcane Experiment: When you scribe a scroll, youre no longer limited to spells you know. You may scribe any spell that you have
access to at the time of scribing (eg, by referencing a spell book, verbally from another mage, etc.).
- Arcane Intuition: When you scribe a scroll, you can scribe spells that you don't even have access to. You can scribe scrolls that you neither know nor have access to by increasing the Complexity of the scroll by 5. The error range on checks to cast from scrolls made this way increases by 2. You may only choose this ability if you may scribe scrolls of spells you don't know.
- Bookmarked Grimoire: You may use a scroll as a Mage's Pouch for casting the spell contained in that scroll, and as long as you have one scroll readied, you are considered to have all scrolls on your person readied.
- Improvised Scribe: You're always considered to have a Scribe's Kit for making Crafting checks.
- Light Reading: Scrolls are considered only one-handed items for you, and the time needed to read a scroll is no longer limited to a minimum of 1 full action.
- Scroll Tutor: As long as they can see and hear you, your teammates may substitute their Crafting skill bonus in place of Spellcasting when casting from a scroll you have scribed.
- Tattoo Inscription: You may make magical tattoos in a way similar to scribing a scroll, except that it is bound to your own skin rather than paper. The Complexity is increased by 5; in exchange, a 'scroll' scribed this way cannot be stolen or removed from you until you cast it and requires no hand to use. A tattoo fades as soon as the spell is cast. You may have a number of scrolls tattooed onto your flesh at a time equal to your Constitution modifier.
At level 10, you may cast a scroll without consuming it a number of times per session equal to your starting action dice.