From past experience I very much doubt that an 8 week old min. schnauzer is completely housebroken.
Although you may have an exception, but at that age and small of a breed I really doubt it.
"Usually" "most" dogs are not completely housebroken until about at least 4 months or so, "usually" longer for smaller breeds as their bladders are much smaller.

When you do decide to not crate him anymore you also want to make sure that he will not destroy anything while you are gone either. Maybe once he is a little older you can just gate up one room for him to be in, eventually give him more space little by little.

Sorry If I misunderstood, but it sounds as if you are teaching him to potty in the house? ON the tray? The only thing with that is you may have a very hard time teaching him to go outside and if you ever put the tray back in the crate you may have a very tough time getting him NOT to potty in the crate as the tray is in it. If your plan is to get him to go potty outside only at some point I wouls stop right now with allowing him to potty in the house.
Even if you are teaching him to potty outside on the crate you may have a hard time getting him to go on grass (in case you go for walks or he ever has to be kenneled etc...) and you would probably still have the problem when you put the tray back in his crate.

I'm not sure what smell you are reffering to, but I think every dog will have an ordor at some point or another. I don't think there is a truly ororless dog out there, it may just of been a selling scam if you purchased him from a pet store or back yard breeder. But it may be caused my numerous things. All puppies have puppy breath, is it that? Maybe he has an ear infection, anal gland problem, getting itno garbage or something, just needs a bath, needs his bedding washed the list can go on & on.

They are good dogs, my ex neighbor has 2 of them, cute smart testy things they are. Good luck!

I would enroll him in puppy classes once he gets his series of vaccines completed, you will need it, they can testy stuborn & too smart for your own good sometimes. Maybe even follow up with beginer obedience class once his puppy class is done.