What are your Loan terms and P/I relative to the cashflow after taxes?

Is this structure standard, though, in terms of capping investor returns at 12%?  

New primary mortgage will be about $2500 a month, old house that I will rent out long term is $1000 a month.

Of the many strategies I've looked into, House-hacking and short-term rentals piqued my interests. 

If that's the case, you should be able to rate/term refinance at ~75% LTV with a DSCR loan, and with some interest-only basis, your payment will go to ~$850 (based on ROUGH pricing TODAY).

Leverage magnifies return. 3) The effort involved in adding an ADU is comparable or larger than a rehab associated with a BRRRR.

What about refinancing  costs or what ever costs that occurs at the end of the loan term?

Long term, your property is going to up in value; likely way up.

RentRedi is perfect for applications and background checks (you can also set clear lease terms and automate rent collection through RentRedi).

A good property manager can help with tenant screening, enforce lease terms, and handle evictions more efficiently if it comes to that.Require a Larger Security Deposit: Within the bounds of local regulations, a larger deposit can provide a cushion in case of damage or unpaid rent.Consider Rent Guarantee Insurance: Some companies offer insurance products that can cover lost rent in case of tenant default.