Fixing finding departure and destination locations
Currently it is effectively impossible to locate "Wilhelminaplein" or "Rotterdam Wilhelminaplein" metro or tram stations. In fact, KTrip will return absolute "garbage" results such as "Amsterdam Sloterdijk" which is a completely different city as well as numerous locations in Germany. This is because anything with a "rotter", "rotterdam", "wilhelm" prefixes or suffixes will match, not to mention any "dam" you care to mention. For possibly the absolute worst case consider anything with "Euro" in its name in Europe...
KTrip should probably prioritise based on whole word matches, and could also be a bit smarter: if it can detect city or town in the name, it could further constrain any matches to within that city/town and perhaps the same could also apply similarly to country/state/province/region names.
Additionally when querying by city name it may be worth biasing towards "Main" stations. E.g for "Amsterdam" return "Amsterdam Centraal" before considering "Amsterdam Sloterdijk" or "Amsterdam Holendrecht". On the one hand this is probably a fairly straightforward heuristic with almost no penalty for getting it wrong (the user just continues typing to refine the search and the search will eventually zero in on the actual target), on the other hand this could also be a bit context/locale specific.
In fact it could be quite locale/location specific. For instance in the Netherlands there is probably a clear bias towards assuming city = its main railway station, so for "Amsterdam" sort as follows: "Amsterdam Centraal" before trying "Amsterdam" before trying "Amsterdam anything else". This is because if the "Centraal" is present it indicates a certain class of station and quality of service/connection associated with this, otherwise any suffix indicates a "region"/location within the city with the main station being unadorned by any classifier/suffix. E.g. for Eindhoven there is no "Eindhoven Centraal" but there is both "Eindhoven" (the main station) and also "Eindhoven Beukenlaan". As it happens this also partially generalises: the "Centraal" suffix is also available under its English alias "Central". I.e. "Amsterdam Centraal" == "Amsterdam Central", at least as far as railway stations in the Netherlands go.