This is one of the photos that we had painted.

Try to be accommodating to their schedule, try not to make a mess, try to respect their right to quiet enjoyment.

Thank you for the respect!

IMO, it is the lack of education (not schooling, but how to clean, teach your kids to respect their living space, etc) that causes the issues, and you have that whether it's a single adult household paying with a voucher, or a two adult household, who both have low pay jobs. 

You will be too detached.5 is required in some states and not in others so a lot if left to your viewing on-site so if you are not seeing it in person, you need full photos and videos of every part of the basement and attic so you have an idea of where the trouble lies before making an offer.

Do you happen to have any photos of the chimney?

My photos are professional.

Always said I respect whatever they think and feel, the product is theirs and they had so much time to decide, to sell it to me or not.

I only have nice photos of livingroom and one bedroom, as I'm still living in the unit. 

A few things you could consider:House Rules: Make sure you have clear, firm house rules for your STR guests regarding noise levels, shared spaces, and respecting the privacy of your LTR tenants.Noise-cancelling measures: You could invest in things like soundproofing the walls or adding landscaping (like thick bushes) along the privacy fence to further dampen any noise between units.Separate Access: If possible, ensure that the STR and LTR tenants have separate entrances or parking areas.