RE: How windy is too windy?
Well, I once flew my Diamond Dust in winds gusting to 45. What a ride. Of course, it hand launches and accelerates vertically, as well as it has the ability to land fairly fast and without landing gear. Down wind passes were phenominal.
But I've been flying models since 1994 and full scale since 2001, and I have the reactions of a 22 year old (i guess because I am one) When I first started flying I wouldn't fly in more than 15 MPH wind, and I wouldn't recomend flying a trainer in much more than that until you are well versed on the sticks.