No realtor would ask if you CAN afford the house. Its probably illegal to do so in Ontario. Its none of their business unless/until you put in an offer.
Shermans' house had been emptied and staged for sale. Its somewhere on an earlier thread that someone who knew them had said 'she really emptied it out' before the Open House. I believe the Open House was a week or two before they were killed. The woman across the road said she had gone over to check it out, check out the decor etc.
IF its an Open House, its open to all. If there is no Open House, then you'd have to call the realtor, any realtor and ask for a 'private showing'. There is NO obligation to show/tell any realtor your financial business. You simply want to see the house.
Human, even 'ordinary' listings have removed anything of value and their undies from the home before listing it. You'd be staring at an empty drawer, likely from a warehouse. Most realtors push for you to 'stage' the house, may or may not be the owners furniture.
Canadian laws and American laws are often totally different and we also vary between provinces, as Americans do states.