I'd like to build a character that focuses on destroying/breaking/messing up inanimate objects (ranging from knocking trees down to collapsing parts of tunnels to making holes in walls, even something as mundane as using Erase a lot to screw up some well-laid plans)-- a de-engineer, if you will. My original idea is an Artificer who will just have a bunch of magical items that let him pull this off. The biggest constraint I'm dealing with is level; the campaign this will be used in is at level 7. This means an artificer could pull off some 5th level spell effects in items, but they'd be insanely expensive.
Allowed Sources: Core, Eberron, and Complete series are a shoe-in. 9 Swords is a no-go, as is Exalted Deeds. Nothing from non-Eberron settings. Other things may be allowed on a case-by-case basis.
Possible Spells:
Stone Shape / Wood Shape are two of my primary candidates
Erase could have its uses
Knock
Disintegrate is too high level; is there a "lesser" version that can still be used to destroy inanimate objects?
Rusting Grasp
Shatter (probably the bread and butter, in conjunction with access to Dispel Magic)
Soften Earth and Stone
Are there any possible abuses of Knowledge (Arch&Eng)?
What about magic or mundane items? The way the PHB reads, no matter how many flasks of acid you pour on something with a hardness greater than 4 or 6 (since it does d4 or d6 dmg, can't remember off top of my head) it won't take any damage because each flask would be reduced individually.
Feats?
Cool tricks?
Adamantine weapon with Sonic Weapon cast on it?
Resonating Bolt (d4/lcaster level damage, 60 ft line, ignores hardness)
I know there is the path of the Destructive Rage smash-everything, but I'd like to have a bit more tactical versatility than just swinging a big weapon at things.
Help!