@BeaultifulNepal,
You got good questions but I can only answer a few based on my experience. You can continue to ignore them until you get served with the legal notice from the court. So, it's up to them on how much they want to fight. For the details on the settlement, please DM me.
Also, as others have mentioned, it also depends on the State of your employer. Not all the states have "non-compete agreement"
I feel I went through the same issue as yours and can certainly share my experience.
Also, I do not really know how the contracts work with vendors and clients, so I cannot answer that.