Are there clearer rules out there for sustaining spells?

I can't find anything in the book that says when a sustained spell is forcibly broken. Nothing about range, line of sight, or duration. The only thing i can find is: "Sustained spells last for as long as the magician concentrates on them."

Here is an exaggeration: Gimpy the Gunbunny has a group of 3 people. Himself and 2 mages. The first mage, Energizer, casts Combat Sense, Detect Enemies and Mindlink on Gimpy. The second mage, Duracell, casts Increase Reflexes, Increase Agility and Improved Invisibility on Gimpy. This puts both mages at a -6 for everything they do, but they aren't planning on doing anything. They plan on waiting in their apartment, safely out of harms way. Gimpy then moves to Mexico to join a higher caliber group of shadowrunners, making sure to send Energizer and Duracell each a check for 3,000nuyen every month.

Also, a slightly related problem: It seems like there is no penalty for casting some spells at force 1 every time, just to avoid drain. Most spells are resisted Spellcasting + Magic hits with Willpower + Counterspelling. For example, Analyze Truth doesn't mention Force at all, other than the drain value. It only requires 1 net hit on your spellcasting test. At Force 1 the drain is 1, and a caster with a magic of 4 can buy the one hit necessary, and can cast it for free, whenever he feels like it.

first off, your hits (not your net hits, just hits... total hits) are capped by the spell's force. so, for example, a force 1 manabolt with 9 hits backing it up is capped at 1. if the other person gets a hit on their resistance test, it fizzles. if not, it deals 2.

secondly, yes you can sustain indefinitely.... provided you don't need to (for example) sleep. also provided the person with the sustained spells never goes through a ward that destroys the spells. which is actually fairly likely. also, those two magicians are crazy if they work for that cheap... 3k a month isn't even middle lifestyle. they're magicians, they can easily make middle lifestyle, and probably even high lifestyle =P

Not to mention that any enemy mages could just dispell the sustained spells.

Well, here is where ritual sorcery comes in. Your 2 battery magi, on the first and fifteenth of every month, perform a ritual to enchant the gun bunny. This is accomplished by a similar method to the coconut bomb. he buys a locket breaks it in half, gives one half to the magi and keeps the other on him at all times. And if they are initiates you get the quickening thing going on for ya. (which is basically what you are going for)

Or, you could just get them to enchant something with those spells. mind you this starts to really suck in the karma.

First, battery magi need sympathetic metamagic for that, which means they are initiates. Why on the first and 15th of every month? Ritual spells don't last longer or anything.

The only advantage to a ritual spell would be that a buff could be applied to a character over a long distance - but it would still require sustaining, and would still be subject to wards, dispelling, etc. Even quickened spells can be dispelled, and those would be an expensive service to buy from a magician - they can be tracked back to the magician (who could then become an accessory to whatever crimes Gimpy has committed), and they cost Karma as well.

From Gimpy's perspective, buff spells are good for giving him a quick boost, but they are unreliable as a long-term enhancement. Gimpy would be better off as either a sammie or an adept as far as combat enhancement goes.

From the perspective of several multi-initiate mages, why waste time buffing someone long-distance when they can summon several high Force spirits to do the job better?

Improve Attribute
Type: P • Range: T • Duration: P • DV: (F ÷ 2) +1

This spell increases an attribute (natural or augmented) on
a voluntary subject. A version of this spell exists for each Physical
and Mental attribute, but not for Special attributes (Initiative,
Edge, Essence, Magic, or Resonance). Th e Force of the spell must
equal or exceed the (augmented) value of the attribute being affected.
Th e attribute is increased by an amount equal to the hits
scored. Each attribute can only be aff ected by a single Increase
Attribute spell at a time.
Note that increasing an attribute may aff ect other derived
statistics (Increase Reaction also aff ects Initiative, for example,
while Increase Body will add extra boxes to the character’s
Physical Condition Monitor

If a mage tries to make a permenant version of a stat increase spell, a man will come and beat him his player him to death with dual-wielded giant trout.

I have only skimmed Street magic so I don't know if this applies in SR4. In SR3 forum this came up before, I suggested then that a magicians maximum sustaning range is the mages maximum spirit control range.

Meh. Buff the sammie, give the spells to your ally to sustain.

Only catch is that they'll set off wards, and that's the cast for any of your alternate methods, too.