The complex has gone thru lot of mismanagement and turmoil in recent years (2018), it is a co-op, and yet to be assured that changes have been made to correct the situation.

If you have any major concerns at any time with regards to your liability, I'd suggest visiting with an attorney that's familiar with these ADA requirements.  

Of course, I communicate with all guests and let them know that since they had such a great experience, just contact me directly the next time they want to visit.

Every time I visit there are no problems, until yesterday.

This option has been presented to me with assurances that many have done the same with no problems.

You would have to force it, ... like by asking them to visit your social media accounts.Instead, if you did PPC, Facebook ads, SEO, Content building, Build a Website with that money, your traffic is pretty much forced to see your web-presence, your authority, your professionalism (if your website is awesome) ON TOP of reaching people asking them if they want to sell... in fact with these venues you don't even need to ask them if they want to sell their house.

This would be to visit properties and take photos/video. 

You can visit the property often if needed.

We have properties in Denver and Colorado Springs, but I really want a mountain home to Airbnb and be able to visit when we want.

Frankly, someone visiting from out of town will likely not feel comfortable having to go to a laundromat in an area that they're not super familiar with.Overall, you want to do things that will help you stand out above the other listings around you.