There are a couple of keyboard shortcuts that come in handy when comping:
Ctrl-T splits a sound.
Alt-Drag to drag a copy of a sound.
Shift-Drag to preserve a sound's time offset while dragging.
Alt-Shift-Drag to drag a copy of a sound while preserving it's time offset.
And of course, the lanes function that you already mentioned.
You can find more keyboard shortcuts in the Mixcraft help file under "Keyboard Controls".
As far as increasing the height of the waveform display, it looks like you already know how to resize tracks. If that's not enough, depending on the track, I suppose you could: raise the volume, mix down that single track, and then import the new louder track into the project.
There are plenty of DAW's that allow you to increase the size of the waveform display. Sounds like a feature request for Mixcraft 7.
Regarding "normalise", Mixcraft does a standard peak normalization. This simply finds the highest peak in the clip and increases the gain of the entire clip until that high peak is at a maximum level (typically 0dB). So, if you have a peak at -3dB and the maximum level allowed by the normalize function is 0dB then the entire clip will be increased by 3dB.