Toe has an effect for sure. But probably won't cure any other problem unless the other problem is very minor.

And toe out will be a problem if it exists. The severity of the problem will also depend on the amount of the toe out and how much leverage the tires have on the airplane.

This summer, a couple of my flying buddies showed up with new cubs. Well, one was a newly assembled ARF and the other was new to the owner. Both of them had toe out, and both of them showed really nasty ground handling. The newly built suffered through a couple of weeks of trying everything but toe. My buddy was positive that he'd assembled the airplane exactly as the book said, and didn't think toe was the problem. Needless to say, when he finally bent the gear to get toe in the airplane stopped 90% of it's ground looping. (If it hadn't, would I have included it in this? naah) And the other one got it's gear bent when it's owner wasn't looking. Who done it? hehehe..... Danged if I know...... And that airplane cut out about half it's ground looping. It probably would do even better if that guy wasn't a FIREWALLING FOOL!!!! He figures there's less chance of having problems on the takeoff if he can get it over with as fast as possible....... right.......

Toe will have more effect when the gear isn't located properly. Most everything about ground handling is worse when gear is too far from it's optimum location. So toe that's not right will be really bad.

Just make sure you have toe in and you'll be ok.