DnD 3.5e Spells – Spells Improving Damage Infinitely with Caster Levels

The spell creates fire and projects it away from you in a cone. The difference between this spell and, say, fireball, is that the fire is no longer magical once it's projected, and thus overcomes Spell Resistance.

Natural fires require fuel to maintain themselves for long. Once the spell is no longer maintaining the flame, it should quickly dissipate, assuming it wasn't cast into a field of dry grass or over a pool of oil. Note that lesser acid orb from Complete Arcane and Spell Compendium is also Conjuration(Creation) with an Instantaneous duration and creates neither an object nor a creature, simply a (non-magical, after leaving the caster) spell effect.

Orb of force is clearly meant to work like orb of acid, although this explanation is going to belong more on Physics.SE than RPG.SE. Force, in real world physics, is transferred between objects when they touch. Ergo, rather than "breaking" or "bouncing off", an orb composed entirely of force should be absorbed by a target (or by the ground or scenery on a miss) on impact. This is what does the damage of the spell - raw kinetic force being transferred to a relatively-stationary target.

Of course, the spell in this case probably shouldn't have the [Force] descriptor, as DnD [Force] has absolutely nothing to do with real-world force, as indicated by the fact that [Force] has full effect on incorporeal creatures and force should have none. If you (or your DM) want to rule orbs of [Force] continue to exist after striking a ghost or object, go for it. (However, both [Force] and force can be assumed to be weightless and noncorporeal, so rather than falling to the ground or filling a ball pit, they should probably keeping bouncing like that one scene in Men in Black until it escapes to outer space...)

1. Your pricing of the small masterwork light repeating crossbow is correct.

   Your pricing of the continuous master’s touch is correct per the guidelines. As a DM, I might not be so sure I like that price, however.

   Your pricing of the at-will use-activated magic missile is correct. However, it would not fire missiles that deal 3d4+1 damage, as you seem to imply. It would instead fire three separate missiles that deal 1d4+1 damage each.

   You have a mistake when you add them together: firstly, you dropped the \$\times2\$ multiplier from the duration note on master’s touch: it should be \$10,000\text{ gp}+4000\text{ gp}\$, not \$+2000\text{ gp}\$. Moreover, you missed this note:

   Multiple Different Abilities

   Abilities such as an attack roll bonus or saving throw bonus and a spell-like function are not similar, and their values are simply added together to determine the cost. For items that do take up a space on a character’s body each additional power not only has no discount but instead has a 50% increase in price.

   For one weapon with two different effects, you need to pay half-again the cost of the continuous master’s touch. So the cost should be \$10,000\text{ gp} + \left(4000\text{ gp} \times 1.5\right) = 16,000\text{ gp}\$.

   Finally, Eberron Campaign Setting has a page (268, to be precise) on warforged components. It includes statements like

   A warforged component usually occupies the same space on the body that a magic item of the same kind normally would.

   Likewise, armbow specifies that it

   attaches to the arm of a warforged, completely covering the hand.

   So assuming that this item uses up your character’s hand like the armbow does, it should cost \$16,000\text{ gp}\$. If it does not,

   Components that do not occupy any space on the body cost twice what they would cost as ordinary magic items.

   Thus that would be \$16,000\text{ gp} \times 2 = 32,000\text{ gp}\$.

   Either way, the fact that the base cost is less than the price of the armbow, despite having significant extra features, suggests to me that your DM may very well dispute these prices. I would.

2. A magic weapon must have a +1 bonus on it before receiving any other special weapon properties. But you aren’t enhancing this as a weapon, you are treating it like a wondrous item. The rules don’t really cover this possibility; I would probably require the +1. But a +1 is all you need; after that, you’re free to put as much other magic on there as you want without needing a higher enhancement bonus (with the exception of the more powerful weapon augment crystals).

   Any enhancement bonus on the item would add to attack and damage, yes.

   For costing these, the fact that you’re adding features to a magic weapon means that you need to consider that 50% premium again. You have a \$10,000\text{ gp}\$ component (the magic missiles), a \$4000\text{ gp}\$ component (the master’s touch), and a \$2000\text{ gp}\$ component (the enhancement bonus, assuming you go with the minimum +1). The second and third each cost 50% extra because you’re combining them on one item. Like so:

   $$ 10,000\text{ gp} + \left(4000\text{ gp} \times 1.5\right) + \left(2000\text{ gp} \times 1.5\right) = 19,000\text{ gp} $$

   This adds onto the \$550\text{ gp}\$ cost of the base item, so your total is \$19,550\text{ gp}\$. Again, twice that if it’s not taking up your hand.