Actually, Quicken Lighting Bolt and Inflict Serious Wounds allows you to do on the same turn as per the rules in just the main handbook.
And by the time you are actually able to Quicken Lightning Bolt as a Mystic Theurge, you're going to be at least 16th level, and have access to 7th level spells, which are far more devastating than those two spells combined.
The reason Punch is more powerful that Fireball is the amount of drain you'd take. Fireball is force -1. So making a fireball of a force 6, you're taking 6 drain per use. Again assuming that you're a human, and you made will or cha/logic your high stat, you'd have a drain protection of 11, giving you 2.75 hits to reduce the drain. Which means you take 3 stun damage generally.
Um, drain isn't the basis of which spells are more powerful. And for something that is F-1, cast at F6, you'd resist 5 drain per use, FYI. Also, remember that enchanting things takes a number of minutes equal to the force, so you get more 'bang for your buck' with AoE spells.
Drain is one of the two parts of what is a powerful spell for these purposes. You've got to have a certain amount of usefulness in the spell. If you have the ability to nuke an entire city from orbit, but you take force +10000 drain, need to sacrifice a two headed baby, erase yourself from existence if you die, and have to have the help of forty other casters just to preform the first part of the ritual... Well, that isn't a very powerful option. It looks powerful, but its completely unusable.
Not saying that a fireball is unusable, but its for the most part impractical in terms of making an "arcane archer" character.
The drain of a F-1 spell is 5. However, FYI, touch adds +1 to the drain, making it 6 drain per use.
Now as you've said, it will take 6 minutes to make 1 arrow. So, if you don't have a lot of time to prepare, probably best to go for bank and use the fire ball arrow.
But time to prepare? In 1 hour you can make 10 force six arrows if you did nothing else.
at 11 dice to resist drain, You're getting 2-3 on average resisted per arrow
So for the Punch Arrows (20 or 30 drain), you're typically capable of shrugging off most of the drain from creating these guys, depending on how the DM rules the +1 drain from a touch prep. Meaning, at the most, you'd probably only need to rest for an hour after making these arrows.
But fireball arrows, would be a total of 60 drain. At 2-3 resisted, you're generally taking 3-4 stun damage per arrow. thats 30-40 stun per hour. Of course you'd have to stop and rest that off, possibly forcefully so after about 2-3 arrows. Your ability to make them also goes down more dramatically than the punch arrows.
Going lower isn't really much of an option either. a force 1 preperation, has a 33% chance of failing regardless of how many hits you get. Force 2 is also pretty high up there. So, you're wanting to make maybe a three at the lowest, at least what I'd say.
In addition to that, because you've got an elemental, you now have to go through Armor + fire protection, resulting in less damage dealt. Though, you do have a nice little rider that there is a possibility of setting something on fire.
Now after hitting, you're going to have to bypass a threshold of 3 for the spell to go off. Which means on average, the spell is going to fail, due to only having 2 hits and being unable to break the threshold.
Nope. Reread the spell section of the book. You roll against a threshold of 3 to avoid scatter. The spell still goes boom, just acts more like grenades.
Basically my ruling would be that you can use normal preparations on arrow heads. Doing so removes the damage of the arrow due to the modifications needed to be able to use it like this. Crit glitching would trigger the spell on you as you touched the arrow. Glitching would allow the target a second defense check to avoid the spell. You only need a touch or grazing attack to trigger the spell. No additional hits are added to the effect of the spell from firing the arrow/bolt.
This allows the rule of cool, right at the start, without having to spend 29 karma on two initiations. Getting the two initiations allows you to be slightly safer, and can pick up your arrows again. Just.. well.. Watch for PDA.
Except this isn't what proponents of the 'magic bolts' have been talking about. And without Anchoring, the only way contact bolts work the way you seem to want is if you are using a crossbow and have someone's drone load them for you (assuming the drone's hands don't ruin the preparation by scratching it). Because Contact works on your aura, as well, so once you put the thing down, if you touch it again, it goes off. 'Rule of cool' is nice and all, but there are a lot of 'cool' things that would simply break the game if allowed, and there's drektons of 'cool' available inside the rules if someone is clever, so I see no reason to change things up.
Don't touch the arrow head. You put it on the arrow head. Don't touch it. Touch everything but the arrow head. Because its the Arrowhead you've enchanted.
If contact worked specifically on aura, it wouldn't require a touch attack to make it go off. You would just simply need to get the touch preparation within the same square as the target. Like how a stun baton works. No matter how powerful the stun baton is, and how much conductive metal the other guy is wearing, if you cannot make a touch attack, you cannot do shocking damage from a stun baton. Likewise with the magic arrow/bolt.
Cause well.. If the GM is just going to go "Nope can't do it because of your aura!" ultimately, touch preparations are completely and utterly useless. Especially with Advanced Alchemy practices (Provided Advance alchemy gets you those trigger types)
Why?
Well one thing I've heard is "You've got to have this thing so you can make it so it triggers only when another aura other than your own comes within contact of the arrow."
Cause, well.. That means you cannot get in the same car as anyone else. Forget about walking down a busy street. An explosive pat on the back. Hugs from Hiroshima. Water has so much microscopic life in it. Anyone punching you or using a natural weapon..
My most favorite way though is Hugar, the Barbarian troll who chucks a kitten at you.
You basically force the alchemist into a position where if he uses touch preparations, He's a walking bomb or he can only make touch preparations on the spot that he wants to use them. Heck, I don't think it would be that far of a step for GM's to ask for a number of rolls as well to make sure he doesn't accidentally set off the fireball in his face.