FWIW, re: wing struts, I was taught to check the strut fairings for cracks as well, on the idea that such could indicate something wrong with the structure... Not sure if that makes sense, but why not... Same thing with the main gear struts, since cracked fairings there could indicate overstress from a hard landing (fairings cracked by excessive flexing).
I suppose it doesn't hurt, but cracks will probably happen under the strut fairings where they are fixed to the wing or fuselage. Cracked fairings are usually a sign of age (brittleness), most older Cessnas you see have cracked fairings as they are so expensive to buy and a pain to install.