1. I have a Eurodmino pass for 5 days. Do I have to use it 5 consecutive days?
No is not obligatory to use your pass consecutive days. Although you can if you desire. You can use the pass any 5 days within the 1 month validity of the pass.

2. If I travel overnight or arrive at the destination the day after I board the train, when should I validate my Eurodomino pass?
If travelling on a train departing after 19:00 which reaches its destination overnight you can validate the pass for the arrival day rather than the departure day – effectively giving you up to 29 hours validity.

3. What happens if I want travel to a neighbouring country from they one my Eurodomino pass is valid for?
The Eurodomino pass will cover the cost of the route up to the borders of the country it is valid for. After this you will have to pay the fare for the remaining of the route.