The best way to estimate expenses is experience and knowledge of your specific asset type and market.For vacancy, that will depend on your market and the quality/desirability of your type of unit.

However neither person is local , they both have filled out applications and seem to check out , but both have "Not for Real ID" IDs which seems like a red flag to me. 

This might be better if you’re uncertain about refinancing or want to keep more liquidity for other opportunities.Since you’ll move in 5 years, it really depends on how confident you are about refinancing.

But strictly going by the numbers, it's borderline OK, depending on the type of market.

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.

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

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

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