How do I use cmd+1 as a keyboard shortcut? cmd+2, cmd+3, etc, work In Preferences > Profiles > Keys
I've mapped cmd+1 through cmd+9 but cmd+1 alone does not respond.

Does anyone else have this issue?

This is for the latest iterm2, v2.1.1 and several earlier versions as well; it has never worked for me.
The problem is that iterm2 uses cmd+1, cmd+2 ... etc for switching between tabs by default. As long as you have first tab, cmd+1 is binded to switch to the this tab.

Workaround is to change Keys -> Navigation shortcuts -> To switch tabs: value to alt or any other except cmd.