Z to switch to connector, X to switch to eraser, up/down arrow keys to switch between other tools, drag to use the connector tool, and for other tools use left/right arrow keys to rotate pieces. Press space to access the block menu, where you can drag blocks around and find the right ones. Need to adjust something, just very slightly? Use WASD to adjust the position of your piece!
MORE PIECES. Drag wires slowly, and if they're missing a dot then click where it's missing Sorry for being inactive on this