Golden Retriever Rescue Education and Training (GRREAT) has a nice PDF that outlines what to look for when buying a golden, and discusses the two fear imprint periods (8 to 11 weeks is the first, and then age 6 to 13 months is the second).
You're hunch is correct about the fear imprint period--it can depend totally on the dog from what I've seen and read.
My response when we're greeted by yappy dogs on walks is to just ignore them--nothing much to see here. I don't make a big deal of it, and I just say "let's go," and/or pat my leg or thigh or clap my hands together and pick up my speed a bit to get my dog going--and when she follows, praise with an "atta girl" or "good girl."
If it's lawn blowers or lawn mowers, and my dog seems to be uncertain of the loud noise, then yes, I'll make a game like "let's check it out! What is this? Let's go see!" and enlist the help of the neighbor cutting the lawn that my dog is a bit shy about the noise and can we play back and forth on the sidewalk while he (or she) runs the mower a bit. When your golden seems to be relaxed and happy--stop--that's success! Then move on--and thank your neighbor.
Same with Halloween decorations--there's loads in my neighborhood--skeleton hands sticking out of the ground--giant pumpkin balloons--tombstones under trees--"what is this? let's go get it!" Obviously, just have her sniff--don't have her destroy! If it helps to bring high value treats on your walk, all the better.
But yappy dogs? She needs to get the cue from you that they are no big deal, and to just be ignored. JMHO.