(Note: I'm a developer of CircuitLab.) It used to surprise me to see just how common it was for people to use general-purpose drawing/diagramming tools for electronics. In fact, Inkscape plus copy+paste is the de-facto schematic tool of choice for the Wikipedia project: https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Electron... ! Nothing against Inkscape -- in fact, Inkscape is what we use to prepare symbols for insertion into CircuitLab -- but it really says something about how painful a lot of electronics-specific software must be that users will jump to general purpose vector drawing tools instead.
Feature request: hold down the space bar to get a drag cursor that moves the whole workspace around. (And ideally also hold spacebar + cmd to get a zoom in cursor, spacebar + option for a zoom our cursor.) These controls are used by every Adobe app (and have been widely adopted by other drawing/graphics software) and they’re amazingly useful, because they make it lightning fast to alternate between moving around the canvas and doing whatever else.
We've currently got Ctrl+Drag (or Cmd+Drag on OS X) for panning around the workspace, and the mouse wheel up/down is mapped to zooming in/out. (Probably need to better document these somewhere!) Compatibility with other keyboard/mouse conventions is something I will pass on to the UI team.
Agree about "amazingly useful ... lightning fast" to switch between modes -- we just added a keyboard shortcut for re-running the last simulation, just so we could eliminate the burden of explicit mode switching between schematic capture and simulation.