He is only 8.5 weeks old and you should not be taking him outside at all for potty! You need to take him to a vet to be seen and have them also look in his ears. If they smell and he is scratching them he might have something going on. As for him scratching his skin I would be concerned with that as well. Where did he come from? Did you purchase him from a breeder? He should still be with him mom up until about 12 weeks old so if you have had him since he was 6 weeks
You need to be careful when you bathe him and not allow water into him ears. Make sure that you use a gentle puppy shampoo. Johnson baby shampoo would not be a good choice it is not properly balanced to his skin. After a bath you need to make sure that he is kept warm and does not get a chill.