Sometimes I click the icons of the launcher by mistake and I have to wait until the program opens to close it again.
How to open the programs in the launcher only if I double click them?
The launcher is not hidden I guess? I would hide the Launcher and lower the sensitivity for popping up the launcher.
And if you hit a button, hit the program that's opening and hit Alt-F4 it's the fastest way I can think of.
No, It's not possible before the application starts completely. You can Press Alt+F4 quickly as soon as it appears to close it.