He sounds bored out of his mind... These are not the type of dogs that can be stuck outside and left to their own devices, they need their people. You can't teach him to behave in the house if you keep out there like others have said.
These dogs especially a full WL NEED a lot of exercise (being stuck out in the backyard does not count!), mental stimulation and a job to do daily. I do obedience exercises everyday(along with being in a class right now) with my pup along with a two hour walk plus playing with him with his flirt pole and giving him puzzle toys and sometimes not even that completely tires him out.
I agree with doing the schuz training now... I'll leave more advice to others better suited but to me he sounds bored and acting out because of it.
~Ollie vom Grunenfeld HIC(8/29/2012)WGSL/WGWL/DDR cross - herding dog in training!