You can reset the watch remotely if you find it in Samsung find or Google find hub. You can also add an additional password, which you'll have to remember should you recover it. A warning though, you can only find the watch if it's on. If it was turned off or the battery died, the best you can do is see the last known location, and you will not be able to reset it or password it.
You can keep checking the apps to see if someone found it and charged it up. Did you have a security PIN on it? If so, it is unlikely someone could get into it even if they did charge it up. If they reset it, as long as you didn't go into your Samsung and Google accounts and log it out, no one will be able to use it, as they would have to log into those same accounts. If you didn't have a security PIN on it, then it could be a problem with someone being able to get into your messages, not so much your wallets, though, as you usually have to provide a PIN to use them.
