Yes, you have to sync your contacts and then you will be able to see your nearby contact.
No, you can only see the live location of contacts that you have added on your trusted contact list.
Yes, there is a feature of sending direct message to your nearby contact.
Yes, you can call your nearby contact directly from the App.
Yes, you can send your live location to any contact through the App.
No, live location can only be tracked of a person added in TRUSTED CONTACTS. You get an approval request when somebody wants to add you, which you can ACCEPT OR DECLINE. Your privacy and security shall not be compromised.