Here's my take on referencing objects/places/people for your art.
DO IT!
Humans have been tracing ever since we put a disgusting paste into our mouths and spat that out onto a cave wall. You think your favourite artists just pull every little thing out of their genius minds?
When I want to use a photo for a reference I look at a number of things. Am I altering the composition sufficiently? If the composition of an image has been artistically crafted, you don't want to just straight knock that off. That's rude. You can, of course, use a great composition as inspiration for your own artwork (eg. referencing the raising of the flag at Iwo Jima.)
I also look at the style. Does the image have a unique, artistic style? Best not to copy that. Is it a photo? Are you going to input your own unique, artistic style, essentially rendering the original photo as a kind of skeleton framework to build on? Where that falls on the cool/kinda shady spectrum is pretty subjective and I believe depends on how much of 'yourself' goes into the final piece. If your art is just straight, even lines tracing over the exact shapes in the photo, you're not really doing much, are you?
As to your question about referencing actual buildings for use in your comic. It'd look weird if your protagonists house was the Guggenheim museum, but yes, if you're using your own photos as reference, it's perfectly legal as long as it makes sense in the story. For me, where possible, I prefer to collect a library of images to gather a collection of attributes that are common to the style of architecture. Then I'll put together the building how I think works best. But sometimes, you just can't do that, and that's okay. For instance, I needed to reference an ancient Ziggurat for my comic, and well, all you have to go off are other people's artistic impressions, in which case, you just do the best you can.