Stolen Iphone

So my phone was stolen two days ago and I took most of the necessary steps to ensure my iPhone is inaccessible. However, I am still very paranoid that the thief will somehow get into my phone so I have a few questions that have been keeping me up and am hoping someone can answer.

1) I put my phone in lost mode, called my mobile carrier, and reported it stolen, but didn't remotely erase it because I thought it would be untraceable if I did. So now I tried to erase it and my question if my iPhone is offline and has no cellular connection (since my mobile carrier blocked it) will the request to erase it go though?

2) I also wanted to change my Apple ID password for extra security, but I am worried if I do it will sign out of my stolen device. Does it sign out of the stolen device and if so, will it still be trackable and will my request to erase my device go through?