Im not entirely sure what you are trying to do and what position you want your icons to be in. Right now you have each one set at varying margin widths / heights and so they are kind of scattered. I removed position entirely, as well as all the margin height, widths that you set and the icons line up in a row.
The reason making a change will affect all icons is if you are adjusting a class that affects all icons, such as icons or fa. also, because of the way you have your positions set, when you change the margins on one, it will change others as well depending on how they are positioned in relation to each other.
I kinda get the feeling though that things started to get a bit complicated with your CSS while trying to acheve a certain effect. If you can explain the goal of how you want them to look then we’ll be able to offer up some advice to get you there