1. The text doesn't mention a range. In the absence of further information, a reasonable guess is the same range as Force Missile (in the original Evocation School, which in turn is the same as the range of Magic Missile, which is Medium (100' + 10'/level). Presumably you need line of effect and line of sight.
2. Since the text says "a straight line", I assume that this means that all objects have to at least start going in the same direction (although conceivably some but not all of them could get diverted).
3. The text doesn't give a limit on number of Alchemical Weapons, other than that they must be within the total weight limit of 1 pound per Wizard level. Note that 1 flask of Alchemist's Fire or Acid or Alkali, or 1 flask of Holy Water (or Unholy water) weighs 1 pound, but 1 flask of Liquid Ice or a Tar Bomb weighs 2 pounds, and a Tanglefoot Bag weighs 4 pounds.
4. Again the text doesn't say directly, but since it says that "Objects are not thrown with enough force to cause damage", the question then becomes whether the type of attack you are trying to pass through Wind Servant's hurled objects needs to do damage in its own right to activate, or whether it can piggyback on any incidental damage done by the objects even when not from the force of their motion. Since Alchemist's Throw Anything(*) gives Intelligence-to-Damage with Alchemical Weapons and Bombs even though these wouldn't do damage if they didn't explode, I would rule that this also works with Alchemist's Throw Anything. In the case of Paladin's Smite Evil or the equivalent, this is more up in the air, but since Sneak Attack can piggyback on attacks as long as they require an attack roll and can do Precision Damage (which splash weapons normally CAN'T do), I would think that by analogy Smite could piggyback on a Wind Servant attack (Smite doesn't do Precision Damage, so it should be better than Sneak Attack in that regard). Sneak Attack has a FAQ whose 2nd paragraph says that Sneak Attack only applies once to each attack, and that multi-missile/ray attack spells each count as one attack and thus get Sneak Attack damage applied to them only once(**). Likewise, according to another FAQ, Smite only adds damage once per spell, and Wind Servant is a Spell-Like Ability, so Smite will only add its damage once for each group of Alchemical Weapons thrown by one Wind Servant attack (although it would still bypass Damage Reduction for all of them when they damage the target of the Smite -- no Damage Reduction bypass for multiple targets unless you somehow already have a Smite that works against multiple targets simultaneously, which would necessarily have to have text that bypasses this FAQ).
(*)Note that Alchemist's Throw Anything is more powerful than the feat of the same name.
(**)Sneak attack can't even be used with splash weapons -- why is this post still going on about Sneak Attack? Well, this madness has a method -- see below.
Still, this ability is not bad if you're set up to use it as you specify.
Now you've inspired me to think of a couple of builds. The first is Underground Chemist Rogue/VMC Wizard (Evoker (Generator)). At 2nd level, Underground Chemist Rogue trades out Evasion to gain the Intelligence-to-Damage part of Alchemist's Throw Anything, but doesn't get the Throw Anything feat (so you need to get the feat separately). At 4th level, Underground Chemist Rogue trades out a Rogue Talent for becoming able to bypass the restriction against doing Sneak Attack with splash weapons. Note that by trading out Evasion, Underground Chemist Rogue also ceases to have any class features that are inhibited by wearing Heavy Armor, apart from use of skills (and situationally other things) that suffer from Armor Check Penalty (no different from any other class trying to use the same abilities), so if you want to start with a Heavy Armor martial dip before Underground Chemist Rogue and then go into Hellknight after Underground Chemist Rogue 4, go right ahead.
Another build you've inspired me to think of is Underground Chemist Rogue 4(*)/Wizard (Evoker (Generator)) 6(*)/Arcane Trickster 10.
(*)Normally you would want to enter after as few levels as possible of each base class, especially Rogue, but you actually need the 4 levels of Underground Chemist Rogue as noted above for the other build, and you need a decent number of Wizard levels to get some weight capacity on your Wind Servant ability, which is not advanced by any other classes. So no 9th level spells on this build unless you go Epic. Also, even with Magical Knack, you will be 2 caster levels behind character level. Since spells quickly evolve (as you level up and gain access to more levels) to become more awesome than any Alchemical Weapons short of those you could get by having actual Alchemist levels, that means this build actually isn't very good. The only way to make it really good would be if VMC were expanded to include archetypes -- VMC Underground Chemist Rogue would get you use of Sneak Attack with splash weapons instead of Evasion (of standard VMC Rogue) at 11th level and still give you Sneak Attack starting at 7th level, and starting with a 1 level dip in Vivisectionist Alchemist would give you Alchemist's Throw Anything and +1d6 Sneak Attack, leaving you with anywhere from 6 to 9 levels of Wizard to increase your Wind Servant weight capacity (and get a Wizard Bonus Feat or Arcane Discovery and maybe even your 8th level Arcane School Power) before going into Arcane Trickster. (The smallest number of Wizard levels is before you get your first +1d6 Sneak Attack from VMC (Underground Chemist) Rogue, and so requires another +1d6 Sneak Attack from Accomplished Sneak Attacker).
^Weird -- I had seen several Litany spells before, but it hadn't occurred to me to look for whether they are Evocation -- intuitively I would have thought they would be something like Enchantment. Actually, most of them are, with a few Transmutation and 1 each of Conjuration, Divination, and Necromancy spells thrown in -- Litany of Righteousness and Litany of Thunder are the Evocation Litany spells. Unfortunately, most Arcane Schools and their Subschools do not have any equivalent to Lingering Spells, but in addition to Evocation, Conjuration does -- as long as you don't pick the Extradimension Subschool(*), Summoner's Charm does for Conjuration spells what Lingering Spells does for Evocation spells, and you even get to pick the Teleportation Subschool if you want, which replaces the lousy Acid Dart power with Shift (although to get the full benefit of this, you will need the Dimensional Agility feat, which means you are out **6** feats instead of "only" 5). The Conjuration Litany spells are Litany of Entanglement and Entanglement, but unfortunately, the latter is Instantaneous, and thus will not be augmented.
(*)For a Tyrant Antipaladin, you could even pick Infernal Binder as long as you found some way to squeeze in a Familiar before you hit level 19, assuming that VMC Wizard V (Conjuration (Infernal Binder)) treats the 7th level Imp Familiar Arcane School Power as the "8th level" Arcane School Power for VMC purposes.
^Oops -- you're right on both counts. Dain bramage -- too late at night. (Like it is again . . . .)