Dear Sun Fei,
I have passed your concern about the shift key on to our engineering team and will inform you once I hear back.
As for creating the Composite, I have created a Composite and have had no trouble viewing the data on the input or output pins. Please to know that, unlike in BRE, you need to click on the numbers, not on the green dots, that follow the outputs of nodes. This is also true of the input pins in a Composite. Particularly, when viewing the data on the input pin below, be sure to click on the number 20, not on the green dot:

For your final point, it sounds like you are using the burger menu, shown on the far right in the photo below:

There are a few bug reports around menu's sticking around after use, and they will hopefully be fixed in an upcoming release.
Hope that helps,
Rocco