Then I go to www.dailyreportonline.com and find the unpaid taxes for the property in the ad as described above.

California has some pretty strict renter laws and ADA laws. 

Is anyone out there familiar with ADA accessory rules and regs?

I am assuming making it ADA compliant (wheelchair ramps, etc.) would be a prerequisite. 

ADA is actually a gray area IMO because are STR's really a "place of public accommodation"? 

Also how does ADA come into play, the property is grandfathered because its in its original use.

Learn about fire suppression systems, door heights/widths, ADA, sidewalk parking, hvac, etc.Figure out how to bring value to the transaction.  

The ADA says true service animals do not require registration, nor can I ask to see it even if they do have it.

Things like valet trash, cable contract reimbursements, RUBs, common area expense budgeting, proper staffing levels, AI revenue management, PPMs, subscription agreements, blue sky filings, commercial lending standards, commercial building codes and permitting, ADA compliance, etc.  

Then jump on landglide or onx and find out who owns the property. idaho, especially ada and canyon county has some funny development laws but a lot split would be possible.