Adam its not a uk problem it's a problem for those hosting and the wftf. There should be a mandatary entry system for all hosts as well as basic things like insurance and medical support. If you can offer that no problem. I've found a few websites that can organise shooting holidays in Nz which state insurance and organisation for the visitor for the visitors firearms license so there should be no problem there for nz to sort the same. Obviously organisers should not want sleepiness nights from being found liable is there was a problem. Contrary to the popular conception that insurance can't be obtained in Nz for instance this document explains about liability and advises it. http://www.sportnz.org.nz/Documents/...y_Document.pdf
With 30 or so years before hosting I'm sure there is enough time to sort the paperwork out like Hungary did. We should remember that although entry may be more difficult in some countries, once approved, gun ownership can be more open and thus ft is able to be shot with ease.
Countries however need to be very clear about what they are undertaking and their visitor expectations. Beyond that and the hosting issues I don't see why a country can't join as I don't see hosting as the sole reason for joining. Indeed for some countries we are looking at decades before they may be able to and the situation could be different for all by then. We have already lost a country due to scoped shooting being effectively outlawed for everyone inside it's borders.