Just got a replacement propshaft put in due to hitting a rock and i run a Merc prop got about 50 miles and my prop has moved back in to the housing and rubbed it and has ate the seal out. Could i have overtighten the prop or has something happened inside the gearcase to cause the shaft to slide in to allow the prop to rub? There is about 1/4 inch movement in the shaft maybe more, is this normal?

The shaft shouldn't move at all. I'd bring it back to the installer.

got the lower unit apart and lost two ears off the gears, they got down into the bearings and got them two. The guy told me to look in a bucket he had and in it was several other gears with the problem, he said that this is a common problem with the hondas and he had a 5 gallon bucket full of proof. I am beginning to dislike my Honda, anybody want to but it when i get it fixed.

he is full of it

I could see thhe broken gears if they were hitting something pretty hard but not just for no reason. It does sound a little far fetched.