
I have a Golden Retriever as well and he is a fantastic dog :-) The fact that your pup asks to go out is a bonus in my opinion as my smaller dog's "ask" is not a vocal one - he stands by the french doors looking out and I have to be very vigilant about making sure he has enough opportunities to go out for a toilet break - as long as your dog doesn't get too vocal a bark to let you know is great :-)
My GR will give one woof to go out and repeat it in a few minutes time if I haven't been able to respond to his request. My other dog can be very vocal but barking to go out isn't in his repetoire - probably just as well with him :-)
I followed the same regime as you with housetraining for my GR puppy and he only ever had one accident indoors and that was because I didn't believe him when he asked to go out - he had just been but obviously that time he needed a two stage tiddle :-)