When you say "is it proper etiquette to ask the seller's agent to share this info with us..." what info are you asking for specifically?

There's no one size fits all approach to real estate investing and depending on your resources, skill set, and capabilities you may excel in one particular market or utilizing a specific strategy whereas another investor will excel using a different approach.  

Balance Sheet is a snapshot of the company's financial health at a specific point in time.Income Statement is a showing us the health on an operating POV.

I wonder if it is feasible to pre-qualify prospects financially and criminally before touring"No, that's a fast pass to getting sued for violating a whole assortment of laws, how many and which all depending on the specifics to the potential buyer. 

I also make it clear we will record inspections with pictures or video.I don't address hoarding specifically.

I am specifically looking at a 1985 Connor Industries home.

I see that you're a developer so if you were to build apartments instead, you might want to look at data specifically for apartments instead of lumping in houses/townhomes.

More specifically, which expense variables are used in the  ratio? 

Is that across the board, or target market specific? 

One other thing to look for in a future architect, is one that has a track record of working with developers AND knows the entitlement processes for the very specific type of development you are doing.