Re the shoe goo, so far it seems to be ok on the actual part of exposed sidewall threads, which is maybe a cm long but not much more than one mm high. I figure even if some of the goo peels off, the stuff in the little worn down section will probably stay in there and essentially protect the threads from dirt etc, and I can live with that, and I can live with putting a bit more once in a while.
but no, will not head off to Mongolia or Scotland with this tire. But that's fine.
thanks though for all the discussion, it is interesting to see people's experiences and views, entertaining anyway.
I'll post how it's holding up when I ride it more. Just busy with family.