Yes it can but, a 12AU7 would make a much better choice as it has the needed plate dissipation. It still doesn't make the unit a tube amp.
absolutely true. the idea is not new though. being English i'll bet that they're aware of Quad and their "current dumping" series of amps that have been around since the 70's. just a guess is all, but those Quads employed a very unique design; a high quality but very small and low powered amp that would piggyback itself onto a much larger "big brother" amp, both of which were in the same chassis. just a guess is all, but maybe Vox got some inspiration from it. the last current dumper, the 909, was discontinued last year http://www.whathifi.com/review/quad-909