Hi! This is my first post ever on Reddit, but I'll give it a try and attempt to answer at least to a part of your question, the second one (about the use of the icons). By the way, english isn't my first language, so sorry if some terms are badly used, but I'll try my best, like I said.

There were some historical events in particular and stuff that happened in the byzantine empire, regarding the use of icons, which either could cause harm to the people, or simply contradicted the christian commandment against idolatry.

For example, during a siege by Arabs (during Leo III the Isaurian's reign), apparently, byzantine soldiers decided to use an icon of the Virgin to "defend themselves". Arab soldiers shot arrows and broke the rope by which the icon was hanging, they picked up the aforementioned icon and started messing around with it. The Byzantine soldiers decided to open the gates to get the icon back, because of its value to them. They were stopped just in time, but if they hadn't been, their whole defense would have been in jepoardy. In itself, this iconopholia could very well have cost them the battle. Unfortunately, I don't have precise sources for what I'm telling you, it comes from a History of the Byzantine Empire class I took when I was doing my Bachelor's degree in History.

As to the way the icons were used, they were used in a variety of ways. Like you said, come people carried sort of amulets around their necks, some people did kiss their icons (like you wrote), but some people went as far as naming an icon as the Godfather or Godmother of their children. Again, this information comes from the class I took, but you can even find this information on Wikipedia, in french, in an article about "art under iconoclasm".

I hope this helps a little, and when I have more time, I'll try to answer a little more :)