Grease Pencil - material, hotkey and modes menu?

Hi,

I’ve started using the grease pencil and am getting frustrated because the line work is going under the geometry I am drawing on, so I can’t see where I have drawn. I know for retopology is it possible to force one material to show above another, but in 2.8 for grease pencil I can not find this setting. Also, even if I select the pen to draw on surface only, if I slightly go off the the geometry the pencil still draws and makes some very messy vectors.

Another thing is that I can’t find a hotkey for draw mode, the user guide I found says “D” key but that doesn’t work for me. As well, if I select an object to edit it, the draw mode disappears from my modes drop-down and I need to select the grease pencil layer from the Scene window to bring it back.

I’ve not used Grease pencil before so I don’t know if these are 2.8 bugs or normal issues.

Any help, much appreciated.
Thanks