^I find that very hard to believe. The only thing that the solder would be exposed to is heat, and the solder material is designed to withstand heat pretty well. So unless that mobo/solder was 10 years old that's not going to be a problem.
It depends what we are talking about for compressed air. If you mean the little dust off cans, definitely not. But if you are talking an air compressor, you might be surprised what a concentrated blast of 120PSI of air will do to surface mounted components.
Also, can't spinning a fan create an electrical current through the wire? That's what I was told once, and was told to always hold them still while cleaning with air.