What are the emergency numbers for police and ambulance?
General emergency number is 112 for emergencies needing assistance of fire department, police or ambulance.
What languages are commonly spoken?
The official language is Estonian. Good understanding of English (young and middle-aged people) or Russian (middle-aged and older people).
Does Estonia have freedom of panorama? Can I safely take pictures of official buildings, trains and planes?
Unfortunately, Estonia doesn't have freedom of panorama yet, and you're limited to publishing pictures of public domain monuments and buildings only (or of ones with OTRS permission). But you can take and publish pictures of trains and planes.
Does the venue have Wi-Fi?
Yes.
How easily can I find Wi-Fi in cafes, bars, etc?
In big cities very easily. Almost every café and bar has Wi-Fi.
