I'm not sure why those hotkeys are listed as requiring the use of the Alt key but the reason your screen is rotating is because that is Alts in-game function: camera rotation.
You can reset it with a single or double tap of backspace... anyway, don't bother with alt. Just hit "." and "/" and set your mouse hotkeys to those. It should work fine that way.
I know the reason for camera rotation. I set ` as Alt+. with autohotkey and it works fine. The strange thing is that the problem persists when I try to use a mouse button instead of `. It is a bummer because ` is still inconvenient for me.
Oh...I did not know that . and / work by themselves. Unlike Alt+., . itself does not move camera to the selected unit's position. Thanks for the information anyway.