Not stretching the strings can cause a real problem with them going flat after you get them to pitch. It seems worse on fiddle than guitar, and worse with the fatter strings. Perhaps they take longer to flatten out along any surface they happen to touch.

As far as tuning - some people do it as a nervous habit. They'll mess around with one string, and I'll sit in the audience and think "no, man - your 5th string's out! Why didncha screw with that one!"

Jed, aren't you supposed to be somewhere else? Michigan, maybe?