To make lifts and powered transport, only 3 new elements the size of one square are needed:
- Tilting floor: need 1 block, 2 mechanisms (and optionally 1 bar): tilts slightly when activated, thereby shoving off any objects 1 square in a specified direction (pick one of north-south-east-west, like catapults). Combine at will to form a conveyor in any direction, add new elements when needed. Alternate their states (flat-tilted) to obtain efficient transport. They would require power, but not an extra row of gearworks/mechanisms to transfer it. Could be walked on normally when flat.
- Rising floor: need 1 block, 4 mechanisms, and 1 bar: The same as tilted floor, but the two states are flat and up, at which point the floor finds itself at the height of the floor, 1 z-level higher.. or against the ceiling.
- Pusher: need 1 block, 3 mechanisms and 1 bar: installed on square 1, when actived pushes anything on square 2 to square three. Much like a rising floor, but horizontal. Useful for pushing objects off tilting floors, onto rising floors, and back off them again.
Combinations of these three could solve most of the demands for automated transportation, would provide more applications for power, can easily be put to other uses (don't tell me you didn't think of what would happen when there was no open space over a rising floor), and are probably (I'm guessing) easier to code tidily and maintain than a contraption that is spread over multiple squares that requires them to function.
(Another idea that came up while writing this: dwarf-sized balancing scales, and their implications.)