Is it possible to plan journeys, routes, itinerary within the app without having to book any actual reservations yet?
Sure you can.
The best though is not to use the app to plan, since it does not get enough updates to be reliable. In addition, some timetables are incomplete because the operators don't send their complete timetables to the European Timetable Centre, most notably Spanish and Italian railways. The best is to use the operators’ own planners; for international planning, the Deutsche Bahn planner is better than the rail planner app, although for Italy and Spain, it will also be incomplete.
Also am I able to plan for the journeys or routes without actually activating it yet till I get to Europe?
Yes, that's no problem.
ANY of the multitude of EUR s railways will have its own website-ever heard of google? Well, you do not even need to know that, as in the country INfo on the main site these are also all linked. Most countries in N-W EUR will even have complete travelplanners for ALL transit to about any sight/adress-but passes are only valid in trains of participating companies-this means at least you can compare.
They will also at the least give connections to direct areas in other countries around. As rian tells-that of bahn.de (=german railways), also that of sbb./com (=swiss railways) are the widest covering.
Oh-and in that good old past a travelguidebook would also tell what connections are readily available to the places you would like to visit-so you can add or cancel them accordingly.
Sounds like I have a bit of downloading to do with different planners and comparing timetables.
Thank you both for the tips and very helpful information! @rvdborgt @mcadv
Will definitely take note of all this.
