Ultimately, it depends on your goals (low rates, fast turnaround, etc.).

It creates over-leverage and the performance of one property is dependent on the other.

@Dorian Gray - I think part of the answer to your question depends on the likelihood of needing more funding in the future and if you have another plan to slowly build up reserve funding.

TAYour ADU application will likely need to be signed by the tenants occupying the property so having a conversation with them is important.

However, this also depends on their ability to prove your neighbor negligent, and the overall cost of the claim.

You don't need to do section 8 to make positive cash flow, but I guess it depends how much positive you want.

And this also may be state dependent, as my  FL property is covered under a different carrier who has different available maximums for liability.

Obviously anything can be negotiated or it depends on what you agreed upon, but what do peers in the industry consider acceptable for this and whats considered unreasonable... 

Main questions should ask about the seller's:- Reasons/Motivations for wanting to sell- Desired timeline to close- Plan's after selling (relocation, reinvesting proceeds, 1031 exchange, etc)- Back-up plan in case they are unable to sell within the desired timeline- Reasons for not already selling to/with a investor or RealtorAdditional questions will depend on the type of seller lead i.e. pre-foreclosure, probate, fsbo, absentee owner, etc.Here is an example of a youtube search you can use to begin finding call recordings.There are 1,000s and you'll find that the best/most effective ones don't even sound like sales calls.

With 3 properties already, you're definitely not "new" anymore ;-) Doing a refi is very possible (depending on how much equity you've accumulated) to do those types of things...the issue can be the tax ramification that you face if/when you do it.