- Eindhoven - Amsterdam is 17,20€ per person in 2nd class.
- No, 5in10 wont be enough... Have a look:
Köln - Amsterdam: 1st travel day
Amsterdam - Strasbourg: 2nd
Strasbourg - Lausanne: 3rd
Lausanne - Barcelona: 4th
Barcelona - Madrid: 5th
Madrid - Salamanca and Salamanca - Portuguese border: no travel days left...
Do you already have tickets to go to Eindhoven? If not, think about going with the 10in22 for your whole trip. If that doesnt work, think about using regular tickets for the parts in Spain, have a look what will be cheapest for you.
- You can make reservations directly at railway stations. I would recommend to make the reservation for Lausanne - Barcelona in Cologne at the station. There you probably can also make reservations for the rest of the trip in Spain (BCN - Madrid - Salamanca). If that doesnot work, make the reservations for the Spanish part in Barcelona.
Also have a look at this topic: reservation-supplement-europe-train-t1561.html
- If you are more than 2 people I'd recommend to book hostels beforehand. Have a look at https://hostelworld.rail.cc
- No, you cannot use InterRail in your own country. But you will get discounted tickets for travelling to/from the border, as long as you have a valid InterRail pass.
- Standard shipping is within a maximum of 7 days, usually it takes 5 days. Express delivery is within 2, maximum 3 days but is 15€ extra...