The Rose support service seems like the right model.Trex is a nice idea but can not see it happening.
We are always happy to take phone calls from customers with queries.
The biggest reason I can not see this happening is cost, people already think prices are too high. Also most distributers are probably not large enough to do this and am sure they would not do it outside of office hours e.g. Saturdays.
Distributers for Bosch bikes do not carry spare parts which is why us and others keep stock themselves. We also stock other parts which our distributers would not stock.
We have had the occasional technical issue with bikes bought a fair distance from us and have normally managed to solve these remotely.
Re Rose sounds like good service. Whether you are local or not people will not go back if you do not provide a good service.
If the UK distributor cannot provide spares and technical support to end users, can't you buy direct from another EU distributor or KTM in Austria? you would surely get good support from them?