At least in cities with adverse regulatory environments like Raleigh, requiring operators must be full-time residents and stay in the property for the duration of a short-term rental, I don't see how this (Airbnb) could scale into a business.

Lease Duration Considerations:Acquire a thorough grasp of the thought process driving recommendations for lease durations.

When you exit a market for a duration (in your case 3 years), you are taking a gamble that market does not get far worse for purchases.  

Even though it may be unlikely that the tenants can buy the community they can take the full duration of time given.

What's your average close of escrow duration?

You get to set the percent of return and the duration.

This is different than paying $250K for an asset valued at $250K which has a return if in produces income.If there is no return, there is no comparison to items that produce a return.I agree that if you are owner occupied for the duration required of SB9, that is likely a better approach than an ADU. 

You might be able to get the inherited tenant to sign off on some new rules and regulations for the duration of their existing lease but I sincerely doubt anyone would agree to anything like a $300/month rent increase if they still have 6 months left on their lease at a lower rent amount.

This includes crucial details such as the rent amount, lease duration, and any specific rules or regulations that they are required to adhere to during their time as a tenant.

Be mindful of including lease duration, whether utilities are included or not, and how maintenance requests are handled as well.