Hi Omar,I don't think anyone is going to be able to give you a summary of the BRRRR strategy well enough to make you feel confident to move forward with your deal, you really need to educate yourself so that you feel comfortable. 

Run your number and make him an offer that your are comfortable with.

You could get a better rate on your rental by converting it to a 15 year if you’re comfortable with the payment. 

If I still cannot get a loan then I will have to get more creative, possibly try to find a seller who is comfortable with using seller financing.My long term goal(like many of us here at bigger pockets) is to someday be able to support myself and my future family with just my real estate portfolio and other investments.

I'm sure it will appreciate well over time since ADU's are still new and in 5 years there will be more properties to compare it to for appraisers - but we are not comfortable with covering vacancy costs that could be up to 7k per mo.

I am financially very comfortable, but the bank thinks I am becoming risky.

I'd rather invest in areas I'm comfortable with.

There is quite a lot of learning and 'legwork' to do to get comfortable in a region, but it is most certainly do-able from Australia!

Ensure your values are aligned with theirs and that you're comfortable with their integrity, ethics, competency, and transparency.

Turnkey is easy but growth doesn't happen inside our comfort zones.