It's not that I necessarily disagree with you Doc, but it's served me well, even in situations where there might be a little wiggle in the wires. In regards to nicking a strand, I would say that it depends on the size of each strand. If there aren't many strands, it might be a little more imperative to make sure you don't knick one, whereas if there are many, nicking one or two I don't see as being a big deal.
Perhaps it's just because my experience is all in audio, using high quality cabling, but I've never been terribly worried about taking a strand or two with the insulation when stripping, because I know that the rest of the strands are in good shape.
Maybe I've just been lucky, but I have about 40 XLR connectors that obviously have tinned ends, as well as many terminal blocks similar to what the OP described in a road case that's traveled all over the country via airline for 5 years. I've never had an instance of a wire breaking at the end of the solder joint. I think we're all aware of the type of luggage "handling" the airline ramp agents are capable of.
In my experience, it's worked well. Maybe it's not the absolute proper way to go about it, but I've never had a problem doing it my way.
I've also noticed that when the end is tinned, putting it in the terminal block seems to mold the solder to fit the shape of the socket and gives it more holding power.
Just my two cents.