Dunno if it's already in the future goals or not..
How many items can a person carry? Well that depends on how heavy, and how large they are. If it's a large barrel, you can only haul one (even empty), but if it's wooden sticks (they are small) you can carry a few as a heap with both hands. (lets say, 5 but it's just some random number). But if you tie them with a rope in two heaps, you can carry two heaps (twice as many), one heap in each hand. 5 small stones in a heap or two buckets with 5 stones each. Weight limitations are still there, and buckets will add to weight. A plate armor is large for hauling purposes while a two-handed halberd is medium (you can carry it with one hand, even tho u cant swing it). And so on.
Furthermore, if a dwarf is using pushcart, the weight he can carry is multiplied while size depends on cart. A larger cart will occupy additional grid. An animal pulling a cart is even better, but it would take two grids for animal and cart, and a dwarf walking and controlling the animal, which takes a special skill. (still, a dwarf with his animal and cart is performing a hauling job). Now that's some use for all those mules! Although carts can't be used on stairs (need ramps).
A ladder is a tricky thing as it can be used differently and I don't know which way would be better in DF.
1) An item any idiot can use. No special skills are needed to just place a ladder so that it stands on the ground at its lower end and is leaning on the floor 1 level higher. It has the same direction limitations as a ramp, also at least one free hand (and at least one leg) is needed to climb it, meaning animals can't do that. (And shuddup about cats, it's an almost vertical ladder, ok?). It's possible to place it from above or below.
The upper grid is a hole for other purposes (drop items etc).
1a) long portable ladders? Not needed tho.
1b) portable ladder in adventurer mode. May become useful as the world becomes more interesting with game development.
2) a ladder can be mounted in place, firmly and vertically, as those fire escape staircases on buildings. It is connected to the floor at it's upper end, raising a bit above it, and at its lower end it's connected to the wall, the floor, or a ladder one level lower to make longer staircase. Not sure about direction limitations (from where to get on/off a staircase), but it has no "empty space 1 lever higher" requirement as a ramp, and a hole with a staircase is still a hole (drop items etc). Mounting a ladder this way may need some skills. Also, one hand, one leg, no animals.
- "One hand" is obviously related to item sizes.
- Someone climbing a ladder will fall down if damaged (an easy target for archers)
- Ladders will prevent animals from going where they shouldn't.
If I were to add something else, items should have a chance to break from falling, depending on material, quality, type and falling height.
PS. sry for my engrish, as it's not my native.