Currently, the Word Complete plug-in can’t communicate with the Snippets plug-in. This is something that we have to improve in future versions.
You can look up syntax functions by using the Project plug-in. The “Parameter Information” button on the toolbar reveals the function parameters when the cursor is at a function.
You can extend the selection using SHIFT + Arrow keys. You can press SHIFT + F8 to switch starting and ending points to move both the beginning and ending points, but I understand you want to move both at the same time. I also understand that you want to move multiple cursors are the same time (as I see from the video). I will add that kind of features in future versions.
Thank you for your comments with screenshots. These are certainly useful.