The only “Arcane Sigil Docent” I can find is from Dungeons & Dragons Online, and is not available in the tabletop game (that I can find, but I have read most of the Eberron books).
Usually a Warforged arcanist would take Unarmored Body, rather than Mithril Body, so as to avoid any Arcane Spell Failure at all. A 5% chance of even casting the spell correctly, on top of whatever chance you have of missing or the enemy resisting, is going to hurt a lot.
Note that if you want to be a bit cheesy (in some groups this would be fine, in others it’d be broken; depends on your group), Dragonborn from Races of the Dragon is an amazing template with Warforged, and would be perfect for a Sorcerer (who usually have some relation to dragons to begin with. Dragonborn replaces your racial features, but you retain any Subtypes you have. Since most of the best features of Warforged come from the Living Construct subtype, they keep all of those, losing primarily the composite plating and Slam attack. Since you want to get rid of (parts of) the composite plating anyway, this is a win-win.
The immediate answer to Arcane Spell Failure is usually the twilight armor enhancement (+1 equivalent), found in Player’s Handbook II and the Magic Item Compendium. It can be applied to Warforged composite armor, and reduces Arcane Spell Failure by 10%.
Other good answers, things like Thistledown (Races of the Wild), Feycraft (Dungeon Master’s Guide II), and Githcraft (Dungeon Master’s Guide II), all of which reduce Arcane Spell Failure by 5%, probably cannot reasonably be applied to Warforged composite armor. Even if they can, they’d almost definitely have to be part of the Warforged’s original construction (though a Githcraft Warforged would be awesome).
Again, note that with Unarmored Body or Dragonborn, you could wear a Feycraft-or-Githcraft Mithral Chain Shirt with Thistledown Padding, which has 0% Arcane Spell Failure before putting any magic on it. This is a great armor.
The Spellsword prestige class from Complete Warrior can allow you to ignore 10% of Arcane Spell Failure; combined with twilight, this reduces your Arcane Spell Failure to 0%. I strongly recommend against taking more than one level of Spellsword, however, since it loses a ton of spellcasting.
Quicksand is a serious threat to a lone warforged who can't make Swim checks.
However, qucksand (DMG 88) initially isn't much of a threat to anyone:
Patches of quicksand present a deceptively solid appearance (appearing as undergrowth or open land) that may trap careless characters. A character approaching a patch of quicksand at a normal pace is entitled to a DC 8 Survival check to spot the danger before stepping in, but charging or running characters don’t have a chance to detect a hidden bog before blundering in. A typical patch of quicksand is 20 feet in diameter; the momentum of a charging or running character carries him or her 1d2×5 feet into the quicksand. [n.b. There is no mention of the typical depth of a quicksand patch.]
So if the warforged is traveling at a normal pace and has at least a half decent Wisdom score, he'll know the quicksand is present and go around it.1 But it's possible, for example, he charges the Valenar horseman who killed his adopted child and plops right in the middle of a big ol' patch of quicksand. That makes things... challenging.
Characters in quicksand must make a DC 10 Swim check every round to simply tread water in place, or a DC 15 Swim check to move 5 feet in whatever direction is desired. If a trapped character fails this check by 5 or more, he sinks below the surface and begins to drown whenever he can no longer hold his breath (see the Swim skill description).
Characters below the surface of a bog may swim back to the surface with a successful Swim check (DC 15, +1 per consecutive round of being under the surface).
Once in quicksand, a creature must make Swim skill checks to move. And, once a creature sinks, before the creature can move, the creature must make Swim skill checks to reach the surface. There's simply no option to walk across the bottom. Everyone--undead, oozes, constructs--must make Swim skill checks in quicksand. The DM can house rule this away, of course, but, technically, that potentially brutal Swim skill check (DC 15 +1 per round below the surface) can make it impossible for the warforged who sinks to escape the quicksand without outside assistance. (A most amusing "death" for the Lord of Blades.)
Pulling out a character trapped in quicksand can be difficult. A rescuer needs a branch, spear haft, rope, or similar tool that enables him to reach the victim with one end of it. Then he must make a DC 15 Strength check to successfully pull the victim, and the victim must make a DC 10 Strength check to hold onto the branch, pole, or rope. If the victim fails to hold on, he must make a DC 15 Swim check immediately to stay above the surface. If both checks succeed, the victim is pulled 5 feet closer to safety. [n.b. This totally ignores the victim's and rescuer's weights, but whatever.]
Obviously, Dungeons and Dragons 3.5 has fantasy quicksand not the real thing.
- If using the Rules Compendium detecting quicksand requires a Survival skill check (DC 15) instead of the DMG's listed Survival skill check (DC 8). The Rules Compendium presents this information without commentary.
Best Answer
Warforged can have gender identities, and many warforged go out of their way to experience “life” in general. For most, this is limited to things like trying fine food and drink, even though it serves no biological purpose for them, but many do more. For example, consider the tracker mask warforged component from Races of Eberron, which grants a warforged the Scent special ability:
Some go much farther than even this, extensively retrofitting their bodies to allow all kinds of biological experiences. See the Races of Eberron section on reforged, with associated prestige class, which in its third and final level has the warforged undergoing a “dramatic physical transformation.”
And, well, “any sexual contact” is quite broad, and even an unmodified warforged is capable of doing things that fall in that category. They may not derive physical pleasure from doing so, but that’s not necessarily relevant, since sexual activity is not exclusively pursued for one’s own personal physical pleasure. Such activities would still break the vow.
Finally, the vow itself makes no mention of it needing to be break-able to be meaningful.
A hermit could take it, for example; he or she wouldn’t have anyone with whom to break it, but I don’t think too many would argue that the vow is meaningless for such a person. For that matter, someone traveling exclusively with companions who are sexually incompatible can still take the vow.
Lack of sex drive doesn’t bar one from taking the feat, either; plenty of real-world people self-identify as asexual, and avoid sexual activity out of preference—and plenty of those have taken such vows.
The vow also doesn’t indicate any ban on eunuchs and the like taking it, and historically I’m quite certain eunuchs have taken roles that required vows of chastity, and those vows haven’t been waived from their requirements just because fulfillment was automatic for them.
Ultimately, the vow means a different thing for a warforged than it does for most people, but they are far from the only people who fall in a category where the vow means a different thing. For some warforged, it would be a difficult vow to keep, or even be one they’d refuse to make. That seems good enough for me.
Even in cases where the warforged eschews all trappings of “fleshy” life, as with warforged juggernauts or the followers of the Lord of Blades, the vow can still be meaningful: just another meaning altogether. There, it would represent the warforged’s dedication to the ideals of its artificial state; after all, sexual activity is derived from the most “fleshy” of goals, procreation.