> SimpleGesture.openExe
That's a good idea.
I will add SimpleGesture.open(url, options) in the next version. (This may take some time.)
for example
SimpleGesture.open('google.com', {
javascript: `alert('hello');`,
inNewTab: true, // default value is true
active: true // default value is true
});

> And if it's possible how much deep can it goes?
Sorry, this may not work in deep.

> setTimeout(SimpleGesture.doCommand('close'),5000);
Try this :)
setTimeout(() => { SimpleGesture.doCommand('close'); }, 5000);

Thanks

UPDATE 2018/12/04
I add a new API "SimpleGesture.open" in version 2.11.
(I changed the name of option from "javascript" to "code", like the "browser.tabs.executeScript" API.)
see
https://github.com/utubo/firefox-simple_gesture/wiki/SimpleGesture.open

Thank you for your suggestion

>SimpleGesture.open("google.com", { code: 'alert("hello");'});
Fix "google.com" to "https://www.google.com"
I thought about adding "https://" automatically, but I stopped.