No You would need to change at either Paris or Brussels. In Paris it is a change of station although they are quite close.
Answer 2I don't think you can get a direct train from Calais to Brussels.
Route 1: Calais to Paris Nord. Paris Est to Frankfurt.
Route 2 (which may be quicker): Calais to Lille. Lille to Brussels. Brussels to Köln (Cologne). Köln to Frankfurt.
Calais
Look to the related link below for a travel guide to Frankfurt .
About an hour and a half
You have a constant speed.
Yes, you can.
You can travel to Frankfurt by plane using the Northwest Seaport.
never
10 hours
approx. 10.30 hrs 1191km
Definitely by car or bus.
it all depends on how you want to travel there.
Unfortunately the question is too vague to offer exact timings as it is not clear whether you are referring to Frankfurt am Main or Frankfurt an der Oder.Assuming you do mean Frankfurt am Main, the next question that arises is which station do you wish to travel from in Frankfurt a.M. and which station is your end station in Salzburg....Assuming you are travelling From Hauptbahnhof to Hauptbahnhof (main station to main station) the shortest journey will take 5 hrs 18 mins. This will involve travelling from Frankfurt a.M. to Munich on the Intercity Express (ICE) and then changing to a Eurocity train (EC) for the rest of the journey.It is possible to travel on one train (ICE) for the whole journey, however the shortest travel time is then 5 hrs 54 mins.The related link below will take you to the journey planner of the Deutsche Bahn, where you can plan your trip and check times.