The standard Windows paradigm to open any “document” is just to (double) click it in Explorer.
Can this be done for an M2MStudio project, or are we stuck with a 2-step process (first start M2MStudio, then use it to open the project) 
This is inherited from Eclipse…
If you use several workspaces, you can create shortcuts as this:
<path to m2mstudio>\m2mstudio.exe -data <path to your workspace>Personaly I use always a single workspace with working sets to avoid switching between several locations.