It might be pain to do a really good modifiable character (lets say the Elder scroll way) whyte a ton of stuff variations to be also collision checked. But, maybe there is a way to widen/slim the box in accordance to the character dimensions and stuff hanging on him (back-packs, gear, weapons). Also i think, that for the weapon and hand-poses, its more a angle-distance based script checking it. Lets say the weapon has 1.20 m length and is in certain direction in the character - you just set the animation to switch to the "holding it along the body" when distance to objects is near 1.20 m and angle of the character right towards the obstacle. A combination of a ton of animations and such characteristics can do wonders, doe, the engine would need some space for those inter-object/persons position computations.
Also, keeping the 80+ bones structure, to give it a next gen. engine mechanics would really need for all those animations some real-world movement capture studio (doe, i think it could be build whyte some low-cost electronics too, when software present for it) - made me think, it would be classy if OT had in future a direct movement animation presentation capability. (you know the IR suits studios, just not getting raw data to a 3DMax animation file, but would take the movement directly onto a character movement rendered real-time in OT -- would make blending animations more interesting and set better when outcome is seen directly in the engine) That may be doing some head-start for future gaming and applications, when real person movement would be used in projection or handling stuff in the engine. (like driving a car whyteout a wheel trough the high-speed 5-cam thingy that was posted a while ago and similar projection technologies, that might come up in future years).